Sunny Side Up 2021

S Association magazine of W.S.G. Abacus

Staff Says

Hans Zwart A Day With...

The Candidate Board Maik Overmars

Solving Rummikub

Sunny Side Up 2021

INDEX 4 4 5 5 6

Columns Educational's Thoughts Your Story!

The Pen Staff Says Pranab 'Praat' Mathematical Mixed Nash Equilibria in Among Us 18 Solving Rummikub Using Integer Linear Programming 22

7 8, 26 13 16 21, 25, 30 24 25 28

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Fun NWS Story Interviews Colour In On the Couch Reviews Christmas Dinner Recipes Christmas Dinner Story A Day With...

Editorial Dear reader, Summer is finally here: the sun is out more often (even here in the Netherlands this is possible), the temperatures are rising, the days are getting longer and I couldn't be any more excited about it!

Why you ask? Well, there are so many different reasons that I'm not even exactly sure myself why exactly it is that I am so glad it is summer. It may be the prospect of finally seeing my family again after a year. It may It may be the fact that the end of my bachelor is now in sight. It could be that I have been looking forward to the holidays for a while now. Or it could be the ability to once again take the time to do simple things such as reading a book outside in the sun.

Especially this last reason has been reason of joy for me the last couple of weeks, just as reading as a whole has been for multiple years now. There is something magical about the way in which certain books are able to suck me in and let me travel to worlds and places I could only dream of. Especially this year, books have truly shown their importance, also because somewhere along the way somebody had me noticed that I've now spent about as much time studying online as physically at the university.

Whenever sitting alone in my room studying would hit me hardest, basically annihilating my motivation to work on anything or even

Colophon Editorial address: W.S.G. Abacus Postbus 217, 7500 AE Enschede Phone: 053 - 489 3435 ideaal@abacus.utwente.nl www.abacus.utwente.nl Editors: Emma Donkers Jorg Gortemaker Tim Hut Daan van Kats Lavinia Lanting Timon Veurink

do anything, it often were books that came in to get me back up on my feet. In particular, my favourite saga, Deltora Quest, showed me once again the bright side of life: it took me to fantastic worlds, had me venture through caves and forests filled with fantastic creatures, it allowed me to walk side by side with the protagonists, but most importantly it granted me 'freedom' and let me finally abandon my tiny student room for a couple of hours.

So yes, books got me through a lot this year and now that the weather allows for it, I am looking forward to bringing one along wherever I go, just to be able to read in the sun.

But whatever the reason may be, I hope that you too are looking forward to your summer and that you will be able to look onto the bright side of things and see the sunny side up of this 'free' summer.

Lavinia Lanting

AGENDA • 24 August Freshmen Bonding Activity • 29 August See you Sunday Drink • 7 September Change GMA • 21 September RSA interest lunch • 16 November Lunch lecture Nobleo • 30 November Lunch lecture BouWatch

Guest writers: Anouk Beursgens (Educational's Thoughts), Jelle Boon (Your Story!), Hans Zwart (Staff Says), Pranab Mandal (Pranab 'Praat'), Thomas Kanger (NWS Story), Jasper de Jong (Mixed Nash Equilibria in Among Us), Ginnie Renz (Review: Euros Sailing), Maik Overmars (Solving Rummikub Using Integer Linear Programming), Christmas Dinner Committee ( Christmas Dinner Recipes), Amalie Zeraïria (Christmas Dinner Story), Leanne van der Meer (Review: Christmas Dinner), Diana Dalenoord (Interview: Clara Stegehuis)

Ideaal! is the magazine issue of Wiskundig Studiegenootschap Abacus and the department of Applied Mathematics.

The responsibility for the articles published in this magazine lies with the original author(s).

The period of notice of Abacus is four weeks before the end of the association year (August 1st).

That means that you must cancel your membership before July 4th. If you have forgotten to cancel your membership before that time, you will pay contribution for another college year.

Would you like to cancel your membership? Send an email to board@abacus.utwente.nl.

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Educational's Thoughts Text: Anouk Beursgens To follow the trend set by my fellow board members, I decided that my piece would also be about the title of the current Ideaal!. However, to do this I first had to find out what “Sunny side up” actually meant. Luckily, we now have google, so I found out quickly that if an egg is sunny side up, it is baked only on one side, leaving the egg yolk still raw. I have no idea if

the Ideaal! likes their eggs like this (I certainly do not), but at least it sounds cheerful and summerish.

It reminds me of a Saturday a few weeks ago. It was one of the first sunny days, so my housemates decided to chill on the roof while enjoying some cheap tequila beers and nice music. Since I am afraid of heights, I had to gather some courage but finally I got up the ladder to the roof. Using an inventive system of a bag attached to a rope, we did not have to climb down when wanting new cold beers. It was a nice re-

laxed afternoon. That day I learned two things: even if they first give permission, the neighbours still get mad if you shoot with a slingshot a water balloon on their balcony and, although the effort put into it is cute, painting a phone number on some sheets of papers and waving it to girls on another roof does, unfortunately for my housemate, not guarantee success.

loaded that nobody could mention one thing that was explained during that breakdown of the coming eleven weeks.

The next day E&M started, were the combination of lectures and tutorials were really good. Not implying that everyone really enjoyed the course, but the organisation was quite excellent. The only reoccurring theme were the answers of the TN professors and TA’s. We just had to make ‘obvious’ assumptions and just accept that some equations denote certain things. The whole ‘logical/ theoretical’ approach that has been hammered into us the past half year was completely absent.

While this was at a few moments really frustrating, it was the goal of the course to introduce us into new way to approach mathematics.

Then onto the programming courses, yes multiple. We had Introduction to Programming and Analytical Programming. First up, Analytical Programming. The goal of this course was to get familiar and to work with Wolfram Mathematica and guide us through how one might use the program to calculate stuff about E&M. Which was really interesting and helpful for the project that we had to, since most things that we had to do translated over in some way. In general, quite a good clear and self-explanatory introduction to Mathematica.

Intro to programming was at first quite confusing. Everybody was questioning what it was that this course wanted to teach us. Which was not helped by the first lecture, where the most students got into an argument with Bodo. However, after that troublesome encounter, both sides began to fathom what was troubling the other. After which the relationship drastically improved and the content of the course became visible for most students.

As for grading, this course was almost completely based on peer review and feedback. Which was really great, because that way the errors that we made were explained on our level of understanding. But which was also really hard, since the correction sheet left a lot open to interpretation. Meaning that if someone deviated from the ‘standard’ answer, grading became nigh guessing. Apart from that small criticism, a nice introduction to the ‘thought process’ of computers and programmers.

Your Story!

Text: Jelle Boon A personal take on the third module After the second module, we as freshmen were hoping for some fresh air after quite a difficult module. This was however not what we found in our third quartile, which was already very clear by the list of courses that we had to sign up for.

Seven courses in total.

It all started with Vector Calculus, where the lectures were often spiced up with online Tai Pan games woven throughout the nearly two hour lectures. For some this meant that they could get some air while they took in the steady flow of information that Jaap was generating out of thin air. Others just focused on the game, since this was a follow-up on the Calc II material that they had already suppressed, forgotten or maybe both. “At least this is not as abstract as Analysis” someone remarked, which was quite the foreshadowing for the end of this module.

Then the intro of Electrodynamics kicked off, where Marc Dhalle gave us a ‘introduction’ to the entire course and project in what felt like twenty minutes. He explained every subject he mentioned in one sentence, leaving everyone so over-

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The Pen Text: Daan van Kats Sunny Side Up! When I heard these three words, I didn't think immediately about that certain way to serve your egg. Instead, it did seem to me more as a sort of saying that you often come across. If you would say it in a more literal way: "Show it at the best way you can", where the 'it' can be yourself or some real object/product that you have made.

Basically, it can go about anything as long as you can show it to other people from a different perspective. It is a more or less common thing at many places; in particular

companies and other organizations. The goal of a company is usually to show their business and the products that they make from the best perspective possible. It is then for us as consumers the job to find out if it actually is all that nice or if there is a shadow side somewhere (far) away from the sunny side.

In our personal lives it actually may be a more useful thought. When you are having it a day a bit harder than normal, it may help to see it from the positive side: 'What is possible to do now?', or 'What did go well today?'. The thing that interests me with all of this is the contrast of it to the language of mathematics.

Maybe in our field it goes less than

anywhere about making a product look 'nicer'. Something satisfies a property or it does not satisfy it. The goal when writing or telling about a mathematical topic is in general to have only a few things, or even none at all, where you could argue about with your other people.

The final thing that I want to share is something I found out after studying more than a year from home: an omelette is much tastier to eat an egg with your lunch. And above all, have a nice, one week extra long, summer!

Staff Says Text: Hans Zwart Learning and un- rize), and things you must underderstanding. stand. The latter makes the logical structure for which mathematics is Last Thursday there famous. Note that understanding was the final of the and learning are not so strongly best teacher award separated as I make it sound here. for the whole of the By seeing the underlying structure, UT. Unfortunately, you understand much better what the candidate from would be needed, and so what is and of AM (and two other studies), part of the definition. For instance, Tracy Craig, did not win, although if you have an intuition, for say, a she gave a very interesting and metric, then you would immedinice talk. Namely, on the evolution ate say that d(x,x)=0, and d(x,y) = of mathematical notation. However, d(y,x), where d is the metric. You that is not the presentation where only have to memorize one or two I want to focus on here; that is the other item of the definition. There is presentation by Maaike Endedijk a nice book about this which I can about the best way to study. At the recommend, Reverse Mathematics end of her presentation, she said by John Stillwell. we should tell the students the conclusions from her talk (and of many As is clear from the above example studies). However, I was thinking; I to learn mathematics, it is better tell the students this year-in year- to understand it. That sounds obviout, but they don’t want to take ous, but how do you do that? The the message home. Although her simple answer to this is by asking presentation focused more on the questions. That is a totally different best way to learn, i.e., to memorize approach than studying answers of things, it can easily be transferred old exams. Important here are the to learning and understanding ma- why and what. What do I have as thematics. ingredients at this moment? Why is this approach taken? Can it not be For me mathematics consists out done differently? As Maaike Endeof things you must learn (memo- dijk also stated in her presentation,

insight does not come overnight. It takes a very regular commitment. It is much better to study the material in small portions, then in one go.

Another thing which I advise every student; study for an 8 or higher.

That brings you to another mindset and forces you to go deeper into the material and leads you almost automatically to the why and what.

The strange fact is that students that study for a 6 (or 5.5) normally end up with a 3, whereas students that learn for an 8 reach their goal.

The above sound like a commitment for only the students. However, realize that it is also a commitment for the staff. We (the staff) must teach and explain the material to the best of our capabilities and help the students when needed. I realize that discussing via Zoom, Teams, etc. is not ideal, and it is much better to have face-to-face discussions.

However, direct communication is possible, and just be happy that we don’t have to communicate via (surface) mail or even pigeons.

So let us make the best of it, and hopefully we see each other again in September. Enjoy the holidays.

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Pranab 'Praat' Text: Pranab Mandal As some of you may already know, I am stepping down as the programme director and will pass on the baton at the end of August. It was not an easy decision to make.

I took over the position in March 2020, right when Corona started to affect our daily lives in the Netherlands. That meant more challenges. As a mathematician my eyes lit up — yay, problems to solve! At the same time worried as any in a managerial post would be — how to tackle them. Fortunately, as a community we found a solution, may not have been perfect but a reasonable one nonetheless. Now that we are coming to the end of the current academic year, the question has appeared how to proceed further. While at this post, I have enjoyed every bit of the interactions I have had with the colleagues, the students, Abacus and many more.

Life, however, requires a decision making process which is multi-faceted.

We can draw the similarity to the mathematical optimization problem. As you know, the ‘optimal’ solution depends on your objective function. Sometimes, though, you want to optimize multiple objective functions. This becomes impossible when two of the objective functions move in the opposite directions. This is, of course, related to the fact that defining an ordered relation for real numbers are much easier than in vector spaces. One alternative proposal from the mathematicians in this situation is to provide a set of so-called Pareto optimal solutions. For these solutions, you cannot improve further on all objective functions simultaneously. If you want to improve on one objective, another objective will necessarily degrade. In life, the most of the situations we come across are similar. They require multi-faceted decision making process. Pareto optimal solutions do

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not help, because ultimately, I must choose ONE of them. We are sent back to the drawing board! An obvious way out is to somehow combine all the objective functions into another one, this time a real-valued one. We then try to find the optimal solution according to the new objective function, knowing fully well that it may lead to a strange or counter-intuitive solution.

One may, of course, try to combine the multiple objective functions differently to see whether a different, albeit more likeable, solution shows up. The fact of the matter, however, remains that not everything in life works exactly the same way as in mathematics. Life is non-anticipative. We cannot run a-priori simulations to look into the future and come back in time to make a decision. One must make a decision now and move forward. Given this, I strongly believe that it is important to look back at the past. However, we should not do so to regret what could have been. That would be a waste of time, we should rather learn from it — what we should do (differently) in the future if we cross the path again.

I reaffirm my earlier statement that I, as the PD, enjoyed every bit of my collaboration with the students and colleagues alike. I would not have it in any different way. We may even joke about the past awkward/ uncomfortable situation, like the anecdotal conversation between an American who is standing outside an office building, and a British colleague who have just come out of it. Desperate to start a conversation, the American colleague started with the weather, but for whatever reason, the British colleague failed to pick up the context: - Spring in the air!

- Why should I? Talking about the weather, we have now passed the winter; currently passing through the spring, slowly progressing towards the summer with hopefully a lot of sun. Draw-

ing the parallels in the context of the pandemic, the slow but steady progress of vaccinations starts to show the ray of sunlight cutting through the winter mist. I sincerely hope that as with my arrival, my departure coincides with the same for Corona, giving rise to a view to sunnier and greener pastures. No matter what happens in the coming period, though, I know for sure that my successor can count on the spirit of you through thick and thin: the sunny side up!

Where are the Abacus members going this summer?

NWS Story Text: Thomas Kanger Organising the NWS was a great experience and we would like to give the reader a taste of our work as a committee.

At the start of September we formed the NWS committee. Our committee consists of Niels Apeldoorn, Margriet Eijken, Hugo Hof, Thomas Kanger, Lavinia Lanting, Maik Overmars and Martijn ter Steege with as the board representative Jorn de Jong.

We have had weekly meetings every Monday during the break. We discussed possible themes and after a brainstorming session we concluded the theme: “Find your

limit”. We looked for locations, worked on contacting companies and orators and made our logo. Next up we started looking for mathematical directions within our theme. We also looked for sponsors that fit within our theme and confirmed the date for the NWS: June 4th.

At the start of 2021, we began with the design of posters and flyers for promotion and created the ideal-day program. We had the first meetings with companies and we made some great progress with the budget since the budget had to be approved at the second General Members Assembly.

During March we started talking with Inter-Actief and Stress about

their online symposium. This gave us a positive impression and so at our Go/No Go moment mid-April we decided to hold the symposium online. We now had to make sure everything would go great for the symposium, so we started discussing with LISA Utwente. For an online platform, we looked at multiple platforms and chose to use Hopin.

Because the event is online we had a lot of spare money and looked for things to put in a goodie bag.

During the last weeks before the symposium, we invited the orators to do their talks live at our studio in the Spiegel or to record their talk at home.

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Interview

The board year for the 53rd board of Abacus comes to an end.

In this interview the board tells us how they experienced this special year.

Text: Jorg Gortemaker and Lavinia Lanting

Before we start: Velthuis, you have made a point out of being persistently very politically correct in past interviews. Can we expect the same again?

every child's wish.

P: Did you manage to become a secret agent?

L: Yes, but I’m not allowed to say that.

V: Why did no one say successful?

V: I don’t know what you are talking Rest: Or rich, millionaire, happy, about, you guys act like I act diffe- board…

L: Secretary and officer internal afrently in interviews. fairs of the 53rd board of W.S.G. Abacus.

What did you want to become V: No one wants to become secretary, not even you would have dawhen you were kids? red to dream that.

A: As a kid I was convinced I wanted L: That’s what you think and I have to be a maths teacher, now I have actually become it, I have tricked decided that I don’t want to do any- you all. thing in education.

Has your board year given more L: Well Jorn.

J: As a child I always wanted to be- you perspective into what ‘working life’ is like? come a monkey, when I was finally convinced that wasn’t possible, I A: The more organizational layers, wanted to become a seal tamer.

P: I wanted to become Bob the buil- the longer everything takes. That der, I also had the helmet. Now I doesn’t give me hope voor communication in the future. only have a white helmet.

V: I wanted to be a farmer when I L: I do agree with that. And the fact that if you read your mail in time was little.

L: Secret agent seemed like fun, I you’re already amazing, that is a have also answered architect, as- real skill. tronaut and scientist. All of those V: You learn the most on the front of working together and how that strange things.

A: I do like that you just mentioned works.

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What was it like being the board? Was it easier or harder than expected?

P: It IS fun being the board.

V: It is way different than what I expected, partly because of covid.

Even if it were a physical year, I think it would have been a different year, I think the division of what is going to take the most time is different from what I expected.

A: Most of the time stuff that you expected to take a few minutes takes longer than you expect.

L: The stigma that you can’t explain well what a board does is true.

You’re busy the whole day, but you can’t really say what you’ve done.

You have a lot of small tasks that you put a lot of time in.

A: And also, when you’re doing the one thing you think of another and you start doing that, that splits in a kind of tree, then you work back and then your day ends.

P: Yes, and sometimes you don’t work back and then you end up with a lot of loose action points.

V: And all of sudden you don’t have a board piece.

A: It started for Pluister with the board piece that made him think of

something else and he hasn’t ever really worked back to the board piece.

What was the nicest moment during the board year?

P: The interviews with the Ideaal!

J: That Pluister finally finished his board piece.

A: The MMM. L: Yes, the MMM was lit, just the build up to the MMM and also finally the nice feeling of a successful activity, finally a lot of people again.

A: And also people that you haven’t seen in some time, because you don’t see them walking near the Abacus room. Also just everybody’s amazement that they could actually walk around in Gathertown.

L: And also that it actually worked, we actually thought that the Gathertown failed. It appeared as though only about 50 people could enter. I have to say, also the after GMA drink was quite great, it was just so nice. It also was one of those drinks where you think around 1 or 2 am “time to go home” and then you start talking with some random people and they offer you some beer and it gets extremely late again, something I would have wanted more this year, but to no avail.

What has been your favourite activity so far?

A: Well, then I will claim the MMM again, because I said it first on the last question as well.

V: Then I will claim Smarter by the second.

L: AMW! P: Christmas dinner was lit as well.

A: And unexpected as well actually, I know how much logistics went ahead of that, that was nice to see.

V: Yes, I also saw some of that, it was quite the hassle. But Jorn, you also have to claim one, you still have nothing.

J: Yeah, I was just looking back through the calendar, but I haven’t

spotted something specific. I don’t want to pick that one because it hasn’t been yet. I just saw the student house games and those were great of course.

V: Why wouldn’t you pick an Abacus activity?

V: I actually also thought the Pokémon activity was quite great.

J: Every lunch lecture was great as well.

All: (Start to name every activity they helped organize.)

L: The music quiz in quartile 1, 50 people came to that one.

P: The terrace tour was also really great.

All: (Start to name more activities they helped to organize.)

Your board year is not quite finished. Anything you’re still looking forward to?

All except for Jorn: AMW. J: NWS. Rest: Come on Jorn.

J: Alright, NWS and AMW V: There has to be something that we still think is really sick.

All: (Start to name every remaining upcoming activity) J: When will the Ideaal! be released?

P: approximately 15 June.

L: Come all to the Bob Ross painting tomorrow, oh wait the enrolments have already been closed.

regardless of what strange online education stuff will happen.

P: That they will find a use for our crisis management document.

L: If you’re reading this back 10 years later, read the crisis management report.

V: You mean, if you’re reading this Ideaal! online, then...

Any tips for the candidate board?

A: Make sure you really enjoy it.

L: If you have really paid attention during the orientation, then all will be well.

J on behalf of P: Read the long term vision document from Abacus.

V: If you can’t work as a unit, then it won’t work. You just have to make sure you have it nice together, then you can handle everything together.

And ask for help from your predecessors if you need it.

V: Oh, and I would suggest 2 teams for the Batavierenrace, with one of them having the old-chairman for the final stage.

A: And also the previous female board member.

V: Anouk, we will make that happen next year.

A: If they have trouble with something, they should say it.

V: Listen to the members, they also have great ideas.

L: Sometimes.

What are your hopes for the What are your plans for next next 10 years of Abacus? year?

V: That we finally have spent all the profits.

A: I hope I won’t be with Abacus anymore in 10 years, I want to be done studying by then.

V: No, in 10 years I want to hang on the wall as an honorary member.

L: I hope to once write the Christmas story as an old dick, so candidate board, pick me.

A: I hope that the interconnectedness and also what we had before Covid within Abacus that that still remains also 10 years from now,

L & V: Finishing the bachelor.

L: Doing an easy minor and going to a lot of Abacus activities.

J: Luckily I still have a whole summer break to decide on that.

V: Launching my pro Rocket League career.

A: Come up with what I want to do with my life.

V: Adding a bunch of people on LinkedIn I learned yesterday.

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Are you joining any (new) com- J: Complaining to somebody else What was your greatest achiethat there is no more coffee. mittees next year? vement this year?

P: Velthuis and Anouk are joining the Bataco next year.

L: I would also like to join the Bataco, but I don’t know if there are any spots left.

P: 53rd Dies is also ours for the taking.

V: I would also like to do the Symposium committee some time.

L: Someday the studytrip committee, if that is ever gonna happen again.

J: I think Pluister would like to join the Casco.

P: Is some one going to join the Abactie?

J: No, because I am not a freshman, so to all freshmen reading this, join the Ab-actie.

V: But for everyone that isn’t a freshman, you can also join the Abactie.

V: Cantus committee could be nice to do once.

L: I would like that as well.

A: Ooh, I like gossip so I am in as well.

J: Oh and the collage committee seems like a lot of fun.

L: The NaCie seems like a lot of fun as well.

Lavinia: Shout-out to Jorn who does all the checking for the Ideaal! nowadays.

A: Shout-out to Jorn who checks pretty much anything I produce.

V: Can I do a shout-out to my mom then?

Lavinia: No.

What are you looking forward to in the coming year?

L: Hopefully doing a lot of physical things again, drinks, activities, just all the big activities.

V: Hopefully seeing people again.

P: Don’t you see people?

V: People I haven’t seen in a while L: And actually studying, I would like that again as well.

A: Planning stuff for myself again, but that seems a bit extreme. Studying for myself.

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V & L: Being an old dick.

P: And giving unsolicited advice.

J: That we can finally go to Texel again, coming year during the AMW.

Luuk, did you finally embrace being Officer Internal Affairs?

Is the Ab-Actie your favourite committee to help?

L: Well, I have spent a lot of time with the Ab-actie this year. Last year I of course said PixCie, but they have reached the same height this year.

P: Luuk will do Ab-actie next year!

L: Well…

V: Every committee is your favourite committee, right?

L: Yes of course. Well, I’m not sure.

Which committee was the most fun helping out?

V: The Freshmen committee, talking to some freshmen, letting them get to know Abacus, always having fun during the meetings.

A: I can’t really choose, with the sports day committee you have the contact with the freshmen, the Christmas dinner committee, yeah, food, recipes, that one’s always great. Prom committee, the effort of the Prom committee is really admirable. Education committee, yeah how could that be different with my function.

L: I have to say, for me helping the Ab-actie was the most fun, I also did the most with them. It was good to see how we kept the spirits high, it was nice.

P: I did not only like my own committees, I also liked to speak with the treasurers of the other committees.

Lavinia: And with which one did you have most fun helping out?

P: I think that I have to say Ideaal! here.

J: I think the NWS or the studytrip.

I do very little as board representative for www.com.

J: That Pluister finished his board piece.

P: That I almost removed Facebook.

L: That we almost have dishcloths with Abacus logos on them.

P: The flip flops of course.

A: The Abacus socks as well.

L: Can you imagine how nice the flip flops are and that they could have been even nicer. They are already so nice as they are.

V: Luuk, we’re a team here, alright?

P: The face masks were also superlit.

V: And everything we managed to do on the front of mental wellbeing, to give a somewhat more serious answer. The appointment of the attentive listeners is also a good development that can be continued also for after covid.

V: The DET-committee P: Yes, I want to join that one.

L: Yes, me too.

What will you miss about being on the board?

L: I did say I’m looking forward to studying, but the not studying is also quite nice. Having courses not has priority number 1 is nice, that you can view as an extra.

P: I will miss that I can abuse my Discord privileges.

L: Abusing the website privileges.

V: That when people wanted to feut you for something you could just answer: “Dude, I’m a board member!”

L: Next year we’ll just respond: “Dude I was a board member!”

J: Luuk, if you join the www then you can still abuse website privileges.

L: Except for when the candidate board does their job right and somebody will constantly watch the quotes site and check if some new quotes have come in.

A: Eline is on the candidate board, I think it will be fine.

J: The nice contact with Carlos from the Subway is something I will miss big time.

L: Jorn, shall we just pick a standard Subway day and then make a deal with him so we can get cheap Subway.

A: The fact that you’re with a group, with whom you share a year of experience. The group chat also gets spammed with meme wars et cetera and that’s pretty great.

L: Are you sure you’ll miss that? I think the connection will remain after this year as well.

J: I’ll miss getting interviewed by the Ideaal!. As board then of course.

tee and a board member.

P: But we don’t have a promotion committee.

V: For this question we do Pluister.

V: Luuk and I remain on top. Pluister and Jorn will stay second.

Lavinia: And the third one?

V: I have told you the top 2, that should be enough. How about, Clara and Jorn and then you can choose yourself who Jorn is.

Were you able to once and for all decide who is the OG Daan?

leave that behind me.

V: Was it worth it Luuk? 200 euros?

L: Doesn’t matter, you shouldn’t have regrets, it was just great.

V: You should learn of your mistakes.

L: Perhaps you should, that’s why I won’t do it again.

V: Also not for 400 euros?

L: See, look, there we go again, no no.

V: Coward!

L: Yes but guys, 5000 euros.

Jorn, do you regret not being What will you definitely not V: Yes, we figured out that it is Daan able to make the entirety of miss from being on the board van Kats so that’s a shame. your board go bald? this year?

P: Yes, that’s my answer as well.

P: Covid.

Rest: Yes, definitely.

L: Specific responsibilities, not necessarily a problem, but at some point it’s nice that someone else gets that responsibility.

P: Then you can finally say stupid things again.

A: We do that regardless.

A: Having to make decisions for everyone is something I won’t miss.

It will be nice when not everyone is dependent on your decision as a board member.

V: I won’t miss that I represent the whole association and that I have to be politically correct, that I can say whatever I want next year.

Do you still think the Officer Book Sales has the most important task?

All: Most definitely.

Anouk: The orientation took a whole 15 minutes, I think it will be a full year task.

You have now spent a year together as a board: what are now the top 3 couples among you?

A: I think that the couples are mainly outside the board. I will go for, the chairman of the promotion commit-

Look at the Ideaal! meetings and the Christmas dinner committee and every activity where he was present.

Velthuis, did you manage to gain the respect of your board and to assert your dominance as chairman?

V: I don’t think you have to show dominance…

L: (unintelligible shouting over Velthuis) V: I don’t think you have to show dominance as a chairman, you have to listen to your fellow board members, making sure everyone is heard equally. I am already dominant in the relationship.

L: With who? Not with Amalie, that’s for sure.

A: With you Luuk.

Luuk, your hair has grown back throughout the year. Do you have any plans to go bald again?

L: No no, but I did realize how much I love my hair, so no, we won’t do that again. However, I did think the shape of my head wasn’t that bad, so if I have to go bald because of natural reasons, then I think I can live with that. I won’t ever go bald again if I don’t have to, I’m happy to

J: Uh, no, not really. That just makes me look way better on the pictures because the rest just looks less.

L: Do you think it’s a shame I was bald on the board picture?

J: No, that just meant we had two bald heads, that gives us unity.

Shouting the whole time: “Bald heads unstoppable!” was nice as well.

L: We were really unstoppable as well.

J: Yes, and now we’ll just change it to: “Handsome heads unstoppable!“

Jorn, how much do you regret not winning the chess tournament?

J: Tja, I mean, it was already a lot better than expected. Top 8 is a lot higher than expected. At least I won from Luuk, that makes it alright.

Lavinia: Will you strive for better next year?

J: I always strive for participation, that is the most important of course.

Pluister, as treasurer we have heard you asking for committees to spend more money How are you planning to spend the remaining money from Abacus?

P: Everyone is a year older drink.

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A: If you as a member still have some great ideas, send them to the idea box. Then we will also have something to discuss under the agenda item “idea box”.

Anouk, were you able to sell any books as a board member with the most important role, or did everyone get their books online?

A: The only thing you have to do as officer book sales is to make sure that the right books are on the website. The rest will be done via the books contract that OS provides.

Furthermore, I hope every student managed to find a way of learning that suits them.

Anouk, as only woman on the board…

J: Wow, did you just assume our gender?

Lavinia: Yes, I will do that, actually.

did do trampoline jumping and I didn’t.

A: If you’re still single and looking for a nice boy, Jorn is still single.

V: Is Luuk officially not available anymore?

L: I’m still available!

A: Oh, well, Luuk is also still available.

V: Luuk, are you polygamous? Just a question.

A: What we would like to say is that we hope to see everyone again and that we also still have a lot to discuss after our board year. And that people will still come to activities full of enthusiasm.

L: fifty-three apostrophe vo!

J: And one of those hashtags that says: #Staysafeforthemémés V: I would like that it says at the bottom of this interview “Sent from my iPhone”. And have a nice vacation everyone.

A: And we suggest that everyone makes the puzzle booklet from the Ideaal!.

V: Is it púzzle or pùzzle?

A: I say both.

L: I always say púzzle, but it is pùzzle.

Anouk, as only woman on the board, are you still the most fe- Sent from my LG smart refrigerator minine or has somebody taken your place?

L: I mean, I have hair again.

A: Well, I still have more hair.

L: Sadly yes.

A: Well, sadly, I hope it will remain this was. I am still of the opinion that it’s a good thing to have different points of view.

Any last thoughts?

P: Finish your board piece if you become a board member. Enjoy life, it’s not such a bad thing to be the most often hungover person on your board.

V: Pluster wants some hype in the chat for trampoline jumping.

L: I would like to say aye aye captain.

A: Maybe I should retract that I’m the most feminine, since Pluister

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Colour In

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Just Abacus things...

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On the Couch Text: Jorg Gortemaker, Timon Veurnink

1. Introduce yourself!

Ju: I am Justus, I am slowly becoming an old member at abacus.

And the Bataco is one of five committees I am in.

M: So I am Marjolein. I am a fourth year abacus student, so I am not that old yet. Daan asked if I wanted to join Bataco and I thought it was nice, because it was an easy committee, and then I was active again.

And I really like running.

E: I am Emma. I am a first year student and the chairman of the sportsday committee.

Ni: I am Nick. I am a second year student now. I am in the PixCie, where we do absolutely nothing at the moment and I am in the sports committee.

Ny: I am Nynke. I am a first year as well and I am the treasurer of the sportsday committee. This is my only committee. It is a lot of fun, but I wouldn't be treasurer next year, only a committee member.

Jo: I am Jorrit. I am a second year student and that is why I am just being present at the sports day committee.

2. How long have you been sitting in your current couch/chair?

Ju: Just in time for the interview.

M: Same, I was just sitting outside and then I had to come inside for the interview.

E: I was sitting at the library all morning, and now I am sitting in my room for the interview.

Ny: I have been at home this morning, now I am sitting here just for the break.

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Ni: The last time I stood up was one hour ago, so now for one hour.

Jo: I also just sit down, because I am at Chendo’s place, and he’s bringing me some tosti’s!

Ju: I actually considered if I wanted to sit on my couch, because I was sitting in my chair for the whole morning already and if I wanted to sit on my couch I had to remove all my clothes and stuff.

3. What is your favorite tosti recipe?

M: I think Jorrit should answer this one because he’s eating tosti’s.

Jo: Just cheese and bacon.

E: I have a favorite with ham, cheese and pineapple.

4. Who do you prefer to sit on the couch with most?

Ny: Netflix!

Ni: I usually sit across netflix, but if you sit next to Netflix that is also possible I guess.

Ju: If I have to sit on this couch; alone, since it is not large enough for more.

5. What is your favorite article in the Ideaal!?

Ju: Of course the two I've written.

Ni: The one I've written.

M: I always really liked Polderpraat.

Ju: I liked the one from Pranab about the history when he went cycling, after he just became programme director. Jan Willem Polderman always wrote about cycling and now Pranab is programme director the first time he writes for the Ideaal! it is also about cycling. And

I generally like the pen articles, just people rambling about some random topic.

6. What was the highlight of your day?

Nynke : This. I have been studying all morning so this is more fun.

Jorrit : I picked up sports day committee shirts today.

E: There is a really nice lunch waiting for me, so I am looking forward to that.

Timon: That is a really beautiful segway into the next question...

7. What will be the highlight of your day?

E: Oké that is my lunch I suppose.

Maybe it gets better later on, but I will be studying so I don’t think so.

Ni: Training tonight, it is outside and the weather is good.

8. What would your perfect lunch be?

M: At this moment, I really look forward to subway lunches again, to pick one up.

Ju: Also when they're not free I look forward to subway lunches.

M: True, but it tastes better when it is free.

Timon: Is tosti your favorite, Jorrit?

Jo: perhaps 9. What is your favorite math theorem?

Ni: Can it be an equation? A bit cliche but I really like eiπ +1= 0, because it has everything in it.

Ju: That is 50% of mathematicians' favorite formula, but I have no clue.

I have to think about all the theorems I have seen.

E: I never stopped to think about what my favorite formula is.

M: Bolzano-Weierstrass, that is the one that comes into my mind right now, I don’t know what that is about anymore, something about subsets…

Ny: I have it here; ‘every bounded sequence of real numbers has a bounded subsequence’. I guess I like the Cauchy, it was pretty handy during analysis.

10. Are you a cat or a dog person?

M: Dog, I am allergic to cats. But I also don’t like dogs, so I don’t know.

I am just not a dog or a cat person.

E: I don’t like cats, but I am also scared of big dogs. I would stay on dogs, but not big dogs.

Ny: I would say dogs, but we have a cat here. I like her too, so I guess both.

Ju: I also don’t have a clear preference. I am also allergic to cats, so I guess I have to go with dogs.

Jo: Dogs.

11. Cayley or Hamilton?

M: Hamilton, formula 1.

Ju: I have to agree.

12. What are you eating tonight?

Ny: One of my homemates is going to cook, so I have no idea.

Ni: We are eating tomato soup.

E: I made a vegetable soup for tonight.

Ju: I don’t know what is on the table.

jolein was busy optimizing the results, because we had two teams putting the fastest people in one team. One person had to go still and we expected that that person would go into the slower team, but that person was quite fast so we had to switch things around. In the first place we needed another 900 meters for the fast team. So Marjolein already was running to do a quick run and then when she got back it wasn’t necessary anymore.

15. What did you thus far like about organizing the most?

Ny: The meetings were very nice Ni: Yes, the meetings were very “gezellig”.

E: I also liked doing the escape room together.

M: All those pictures people send after they did their run.

Ju: But we also still have a committee outing planned.

16. Is there one final message you want to share with the readers of the Ideaal! ?

E: Join the sportsday.

M: I guess, join a committee, because joining a committee is a lot of fun.

Ju: Then I would comment for those who read this after sports day, please congratulate me with winning the sportsday.

M: Make sure Justus doesn’t win the sportsday.

Jo: If his team wins then only disqualify Justus.

13. What are you going to do next?

Ju: I am going to have lunch.

Ny: Getting sports day equipment.

E: Have lunch and go study somewhere else.

Jo: Make a very good project with Chendo.

M: I am going to cycle 14. What is a funny story that happened during organising?

E: Today, the guy from shirts got confused, and now the shirts are reversed with the names and the Abacus logo.

Justus : The 900 meter sprint; Mar-

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Mixed Nash Equilibria in Among us Text: Jasper de Jong Introduction Over the past few months, I have played a lot of among us with students on the Abacus discord server. While doing so, I started thinking about the best strategies. In this article I analyse a specific scenario from Among us, using game theory.

If you enjoy among us, this will be a great introduction to game theory. If you enjoy game theory, this will be a great introduction to the game. If you have no experience with either, that’s even better: You’ll learn twice as much!

Let’s start by explaining the game.

Among us is an online social deduction game. The majority of players (the crew) are trying to achieve a common goal on a spaceship: They win together by either completing a set of tasks, or by voting out the impostors. The impostors look and act like the crew (so the crew don’t know who the impostors are), but they have the option of killing crew members and sabotaging parts of the ship. They win together by killing/voting out crewmembers until the number of remaining impostors equals the number of remaining crew, or when they sabotage the ship and the crew does not fix it in time. If you want to know all the rules and more, you can check www. among-us.fandom.com. However, to follow my article, you don’t need to know the exact rules. I explain all the relevant rules in the model.

I really enjoy social deduction games, and they have taught me valuable life lessons: becoming aware of my own biases. Sometimes I misremember things, or make wrong assumptions about people’s motivations. When this happens in social deduction games, I get proven wrong, I reflect, and I learn from my mistakes. However, one is unlikely to get ‘proven’ wrong in real life. Whenever it becomes likely that somebody is wrong, they could blame the institutions that make claims that contradict their world

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view. This can cause some people to believe in conspiracies.

I like to think I would not have become a conspiracy theorist regardless, but feel that playing social deduction games has decreased the probability, and helped me to stay (relatively) humble.

Also, awareness of your own biases can help you become more objective in your own research.

In many social deduction games, the deduction-part simply consists of noticing that some players take slightly longer to come up with what they want to say (since it is harder to construct a lie, than to tell the truth). What I like about Among us in particular, is that the deductionpart also consists of interrogating players about their location on the ship at certain times. Moreover, there is a lot of strategy involved into decisions like how to use sabotages to your advantage.

The latter is especially interesting from a game-theoretic point of view.

This brings us to the main part of this article: Analysing the use of a reactor sabotage in a 1 vs 3 game.

The basic model By 1 vs 3 game, I mean that there are 3 crewmates and 1 impostor remaining. In this scenario the impostor only needs to kill 2 crewmates to win. However, after a kill the impostor has to wait for his killcooldown before he can kill again.

In Figure 1, you can see on the bottom right that my kill cooldown is 13 seconds. If a crewmate were to enter the room before that, he would be able to report the body, starting a meeting. During a meeting, one player can be voted out. If the reporting crewmate saw me standing next to the body, he should be able

to figure out that I am the impostor, and convince the other crewmates to join him in voting me out.

However, if I were to sabotage the reactor on the other side of the ship (which an impostor can do from any location), this might cause the crewmates to go to the reactor, giving me enough time to get a second kill before somebody finds the body.

As soon as I sabotage the reactor, the screen starts flashing red, and a timer starts. Two players have to stand on two specific positions at the same time (see Figure 2) before time runs out to prevent a meltdown (a meltdown would cause the crew to lose the game).

However, they do have another option: If one of the crewmates finds a dead body, they can start a meeting, which also prevents the meltdown (This is not very realistic, but it makes for an interesting game).

In game theoretic terminology, we say each crewmate has 2 pure strategies: fixing the (R)eactor, and (S)earching for bodies. In social deduction games, it is often beneficial to be unpredictable. Therefore, we consider mixed strategies: A mixed strategy is a probability distribution over the pure strategies. We denote by s the probability that a crewmate chooses to search for bodies.

Therefore the probability that a crewmate chooses to (try to) fix the reactor is 1-s. Note that we use the implicit assumption that each crewmate uses the same probability s.

Now for the possible impostor strategies. I have used both of the following pure strategies with varying degrees of success: - (K)illing a crewmate, before sabotaging the reactor.

- Allowing the crew to (L)ive, and sabotaging the reactor.

For the mixed strategies, we will use l as the probability that the impostor does not kill before sabotaging the reactor. Therefore the probability of killing is 1-l.

We are going to determine what is called a (mixed) Nash equilibrium.

That is a strategy profile (an ordered set of strategies, 1 for each player) for which no player can increase their own win percentage by deviating from their own strategy. Simply based on this definition, Nash equilibrium strategies feel like ‘optimal’ strategies to play. It is actually not that clear. In the conclusions I comment on how to interpret them.

In order to find a mixed Nash equilibrium, we first determine the winning probabilities for every possible combination of pure impostor strategies and number of players who search for bodies. In Table 1, the nu mber denotes the probability that the impostor wins in that situation. That is, a 1 denotes an impostor win, and a 0 denotes a crew win.

To fill this table, we do need some more assumptions: When the impostor does not kill, and 0 or 1 crewmates search for bodies, the crew is able to fix the reactor in time. In practice, any team could win in this situation. However, we assume that the crew is close enough to completing their tasks that they will be able to win guaranteed. Therefore the two bottom left entries (L0 and L1) are 0.

When the impostor kills, and at least one crewmate searches for bodies, the body will get found. Figuring out who did it is not always as clear: The impostor does not usually stand next to the body. However, we assume that the impostor is a terrible liar, and the crewmates are able to vote him out with

100%-accuracy. This occurs in K1 and K2. So these entries are also 0.

Note that this feels like our least realistic assumption yet. However, this gives us a lower bound on the probability that the impostor wins the entire game. In the conclusions, I comment on the consequences of this lower bound, and in extensions I provide ideas on how to obtain more realistic values.

The impostor wins when he manages to kill one player, and no crewmate is searching for bodies. Therefore, entry K1 is a 1. The impostor also wins if he does not kill, and at most one player tries to fix the reactor. Therefore, entries L2 and L3 are 1.

Finally, K3 cannot occur: When the impostor kills before sabotaging the reactor, there are no 3 crewmates left to search.

In order to find our Nash equilibrium, we need 2 observations: First, in any Nash equilibrium, no player plays a pure strategy. This can be seen by contradiction: Suppose that the impostor always kills in the Nash equilibrium. Then the crew would always search for bodies. But then the impostor would always let the crew live, contradicting that he would kill. By the same type of argument, we can prove that the other pure strategies cannot be played in a Nash equilibrium where all crewmates use the same probability s of searching for bodies.

Second, any two pure strategies that have a non-zero probability in the Nash equilibrium have to result in the same win percentage. The reason for this is that if for some player, one pure strategy would have a greater win percentage then the other, he can improve by playing the pure strategy with the greater win percentage.

Based on these observations, we determine a Nash equilibrium by equating the win percentages for both pure strategies. We first determine the impostor win percentage when he kills K(s), as a function of s, the probability that the crew-

mates search for bodies. , since this is the probability that neither of the crewmates search for bodies.

Next we determine the impostor win percentage when he does not kill, L(s): , since this is the probability that only 1 or 0 out of 3 crewmates try to fix the reactor.

Setting L(s)=K(s), we obtain s*≈40.3% as the only root between 0 and 1. As we will see, this is the Nash equilibrium probability for crew­mates.

Now for the impostor Nash equilibrium probability. In order to find it, we equate the win percentages for the pure strategies of a single crewmate. First note that we can simply equate the impostor win percentages, as they equal one minus the crew win percentages. Second, note that we need to take into account the Nash equilibrium strategy of the two other crewmates. Luckily, we just computed it: We simply use s*≈40.3% as a parameter.

We first determine the impostor win percentage when a specific crewmate searches S(l), as a function of l, the probability that the impostor does not kill:

, since, if a crewmate searches, the impostor wins only if he does not kill, and 1 or both other crewmates also search.

Next, we determine the impostor win percentage when a specific crewmate tries to fix the reactor R(l), as a function of l: , since in this case, the impostor has 2 outcomes where he wins: 1. He kills and the other crewmate tries to fix the reactor as well 2. He does not kill, and both other cremates search for bodies.

Setting R(l)=S(l), we obtain a direct formula for l*, the Nash equilibrium probability that an impostor does not kill:

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Substituting l* into S(l) or into R(l) yields an impostor win percentage of 35.6%. This is the same percentage we get when we substitute s* into L(s) or K(s). This is verification that we have indeed found our Nash equilibrium: For any player, deviating to a pure strategy does not improve his win percentage (it stays 35.6%). Also, the win percentage of any mixed strategy is a convex combination of the win percentages of the pure strategies, which is also 35.6%.

Extensions to the model In the basic model, we assumed that the crewmates are able to win the game by completing their tasks when the impostor does not kill, and they fix the reactor. However, completing all tasks can take quite some time. Suppose that instead, the impostor has time to do a second sabotage before the tasks are completed. We can quite easily adjust our basic model to take this into account. In Table 1, L0 and L1 should now be the actual probability that the impostor wins when the game continues. And finding this probability is easy. In fact, we just computed it: 35.6%.

We only need to adjust K(s), L(s), S(l) and K(l) to include this probability. You can find the results in the conclusions.

Note that if the reactor is fixed once and the game continues, the players should revert to their previous probabilities.

Also note that we can apply this process iteratively to find si*, li* and win percentages for i=1, 2, 3,… , where si* and li* respectively denote the Nash equilibrium probabilities that a crewmate searches, and that an impostor does not kill, when there are i remaining sabotages until all tasks are complete (the first of which involves these probabilities).

We can also use a more realistic probability that the impostor wins after a dead body is reported (K1 and K2 in Table 1). Again, we only need to adjust K(s), L(s), S(l) and K(l) to include this probability. How­ ever, the actual probability will de-

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pend on the group you’re playing with, as well as specific information per game. For example, players who were seen close to dead bodies should have a higher chance of getting voted out.

Instead of guessing the win percentage after a body is reported, we could also try to compute it using Nash equilibrium strategies. For this, we have to extend the model to include voting strategies: Crewmates choose their voting probabilities on players based on who has fixed the reactor and/or who has reported the body. The impostor strategy has to include the option of fixing the reactor or reporting a body himself. While this will decrease his chances of winning outright, this will help him when a body is reported.

This is only a high-level description.

Details of voting strategies are not trivial to model, and we might need more advanced techniques to find a Nash equilibrium in such a model.

Conclusions First of all, our basic model shows that an impostor who is a terrible liar, still manages to obtain a win percentage of 35.6%. Moreover, I have used the first extension to the model to compute the following: When there is time for 2 sabotages, the impostor win percentage increases to 49.3%. Amazingly, in this bluffing game, someone who can’t bluff is able to win about half the time through the sheer power of mathematics!

Because of this, I recommend the crewmates to be more aggressive in voting off players when 4 players remain. This has been uncommon in the games I have played so far, probably because voting out the wrong player causes a guaranteed loss (since the impostor will kill the last person before another meeting can be called). However, if you are at least 50% certain about the impostor’s identity, you increase your win percentage by having him voted out, so you should play accordingly.

Second, I have computed more rea-

listic win percentages for impostors who do know how to lie. I am using a probability of 30% that the impostor is not voted out in a meeting.

The Nash equilibrium probabilities and win percentages are shown in Table 2 for different numbers of remaining sabotages until all tasks are completed.

Note that these values do make intuitive sense: When the impostor has fewer sabotages remaining, his win percentage decreases. As a consequence, as the number of remaining sabotages decreases, he should increase his probability of killing, to avoid losing on the crew completing their tasks. To counter this, as the number of remaining sabotages decreases, the crew should increase their probability of searching.

And now for my recommendations on how to use this table. I would try to figure out how your opponents are deviating from these probabilities and use that to exploit them.

For example, suppose you’re the impostor playing against 3 crewmates who play this game for the first time. Some people are not able to locate the reactor, despite the big flashing red arrows. Their probability to try to fix the reactor is a lower than the Nash equilibrium probability, so I would exploit this by not killing.

If instead, you’re playing against 3 crewmates who have played 5 games each, I would expect all of them to rush to the reactor. Their probability of trying to fix the reactor is higher than the Nash equilibrium probability, so I would exploit this by killing.

When playing against experienced players who have read this article, I would initially play the Nash equilibrium strategy myself. If you obser-

ve that some of them are likely not using the Nash equilibrium strategy, you can start exploiting them.

For example, if you observe that they search for bodies in far over 26% of cases when there is plenty of time left, then I would not kill.

If you are a crewmate, it is a lot harder to exploit your opponent, as you do not know who it is. Still, you might have an idea how to do it based on the average level of the other players.

When you are playing as crew against experienced players, it is even more important to play a Nash equilibrium strategy, otherwise they will start exploiting you!

Readers who are not used to Nash equilibria might be puzzled by this advice: I recommend using the strategy described in this article specifically against players who have read it. Wouldn’t they be able to anticipate, since they know your strategy?

This indeed sounds puzzling, but that is the power of the Nash equilibrium. Even though your opponent knows your strategy, by definition his best counter is playing the Nash equilibrium strategy himself.

If you’re interested in game theory, you can learn more in the minor Web Science, as well the master course Game theory.

Finally, if you’re interested in Among us, feel free to join us on the Abacus discord server. We play on most Saturdays at 20:30. Even if you don’t completely understand this article, don’t be intimidated: Strategy is only one of many aspects of this versatile game. You could still beat me using your skills in lying, interrogation, memory, dexterity, persuasion, and/or other skills that I’m not even aware of.

Review: Euros Sailing Text: Ginnie Renz I like to take little holidays from time to time. One of my favourite trips was when I and my friends rented a boat and lived on it for a week. It is quite creepy to sleep on a little boat in the middle of nowhere, but because of that, we got to be where not many people visit. On this trip, many things happened. We lost our engine, so we had to cross a little lake with sails on (terrible idea) and because of that, we ended up getting our boat stuck in the sand and a swan chasing us. Overall, lots of fun. Therefore, when I realised that there is a sailing association in Enschede, I got very excited. I wanted to join it right away but I was always finding some excuses why not to.

Eventually, I joined and I immediately regretted I didn’t join sooner. All

of the sailing I missed out on ! The sailing association D.Z. Euros offers weekly sailings on the Twente canal on little one-person boats, lasers, and in the weekends, in the sailing season, you can join a weekendlong sailing on one of the bigger boats the association has placed in Akkrum. During such a weekend you get to sail a boat 6 meters long which can comfortably accommodate up to 6 people. Since to sail a boat, you need two people at most, it is a great opportunity to enjoy the wind, sun and to get a bit of tan. The most peaceful moment one can experience is when lying on the boat near the sail when the wind is just strong enough to sail and the boat works perfectly. However, the most interesting moments on a bigger sailboat are when something happens. If the winds are a bit stronger, but not too strong, it is lots of fun to sail almost against the wind when

you can tilt the boat and enjoy how the sails are working. On a smaller boat, like a laser, for example, this is much harder. The boat is much smaller and weighs much less too.

Most people start their adventure with smaller boats and are aware of their limits. I, on the other hand, have started with sailing bigger boats first and had to experience the smaller boat’s limits. So on my first-ever laser experience, the moment I tilt my boat, the sail got into the water and I got to swim instead.

Sailing is for everyone. Whether you’re a bit lazy and still want to say you’re doing sports or whether you want to put lots of effort into it and work out a bit. I think that what makes sailing beautiful and fun. You never know how lazy a person can be until you get on a boat together .

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Solving Rummikub using Integer linear programming Text: Maik Overmars At the start of this year I played some rounds of a game called Rummikub. I wasn't very successful however and I lost most of them. I wondered if we can use mathematics to do better. Here I want to talk to you how I approached this problem using topics I learned during my studies.

The game of Rummikub Before we get into the mathematics and the model, we first need to know how the game of Rummikub works. You may already know the rules, but I will explain the rules that are most important for us.

Rummikub consists of 106 tiles, of which 104 are numbered with values of 1 through 13 in 4 different colors (Black, Blue, Red and Yellow/Green) with 2 copies each. The final 2 tiles are jokers, which can be substituted for any other tile. Players start each round with 14 tiles on their rack and the first player to play them all wins the round. Tiles can be played in sets, of which there are 2 types: 1. A combination is a set of tiles with the same number but different colors. These must have a size of at least 3 with a maximum of 4 because we have 4 colors.

2. A run is a set of tiles of subsequent numbers of the same color. A run must have at least 3 tiles.

In a players' turn a player can either play tiles from their rack or pick up a tile from the stock to add to their rack. Any played sets will be put

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onto the board. The most important rule for us is that we are allowed to not only play entire sets, but also change existing sets on the board.

The only requirement here is that at the end of our turn, only valid sets remain. An example is given in Figure 3 in which we can: • play the entire combination of Black 13-Red 13-Green 13 • add the Red 12 tile to the set Red 8-9-10-11 • take the Blue 1 and Red 1 from their sets and play it together with our Black 1.

• exchange the joker with our Red 7 and use it to play more tiles from our rack, such as Black 2-Green 2-joker.

Notice that after each play we are only left with runs and combinations of at least 3 tiles. Our goal will be to play all of our tiles as soon as possible. Thus, we will look at the following question: How can we play as many tiles as possible, while maintaining valid sets?

Integer linear programming In the question we notice two things.

First of all, we want to optimize something, namely the number of tiles played. Secondly, we have a restriction on how we can play the tiles. This immediately lead me to think about linear programming. In a linear program we also have an objective to optimize, while having to satisfy a set of constraints. The final part we need for our problem is that the variables are integers. In our Rummikub case we can't play half of a tile for example. This is why we need integer linear programs

(ILP). You can also have a mix of integer and real variables, which lead to mixed-integer linear programs (MIP). For now, we will focus on ILP's, of which the canonical form is given as follows.

The theory on solving these ILP's is an extension of the Simplex method used in linear programming.

The method used is called branchand-bound, which works by solving many related linear programs using Simplex. This might seem inefficient, but we don't have to run Simplex from the start on each of these linear programs because they are related. Along with some other techniques, ILP solvers can actually be very fast depending on the problem. I won't discuss the theory further here, but if you are interested in these ILP's and the theory behind them I recommend taking the Master's course on this topic.

The model Now we want to apply integer linear programming to the case of Rummikub. When I was looking into designing the model I also searched if someone had the same idea to apply ILP on Rummikub. As it turns out, it had been done before and I found an article [1] on this precise problem. I based most of this model on this article, so if you are interested you can look into this. Recall that our objective is to maximize the amount of tiles played from our rack, while the constraints should ensure that we only play valid sets.

To formulate the ILP we need to know 4 things: the variables, the objective, the parameters that encode our board and rack state and the constraints.

For all quantities we will index the tiles by i = 1, ... , 53 as there are 53 types of tiles and index the type of sets by j = 1, ... , 1173. We will see later how we arrive at that amount of sets. Our ILP will have the following variables:

• For each tile i we let yi ∈ {0, 1, 2} be the variable which denotes how many times we play this tile from our rack onto the board.

• For each type of set j we let xj ∈ {0, 1, 2} denote the number of times this set will appear on the board.

The objective is now quite straight forward to define. We maximize the sum over tiles played yi, or mathematically we have max ∑53 y . Moi=1 i ving on, we need to define the parameters that encode the state of the game.

• The parameter ri ∈ {0, 1, 2} denotes how many times tile i appears on our rack.

• The parameter ti ∈ {0, 1, 2} denotes how many times tile i appears on the board.

To ensure valid sets in the constraints, we need to enumerate all the valid sets. To do this, we need to distinguish between the different types of sets and how many tiles are in this set. We also have to look into the cases of 0, 1 or 2 jokers. Enumerating the combinations is quite straightforward. As an example, consider a combination of 3 tiles of different colors with 0 jokers in the combination. Per number, there are 4 options for these 3 colors: Black-Red-Blue, Black-RedYellow, Black-Blue-Yellow and RedBlue-Yellow. If we then consider 13 numbers, we get 4*13=52 sets.

Runs are more difficult, because they can have up to 13 tiles. Fortunately each run with more than 6 tiles can be split up into runs of lengths 3, 4 and 5. For another example, we look at runs of 3 with 0 jokers. For any color, we have the runs 1-2-3, 2-3,4, . . . , 11-1213. In total, this leads to 11*4=44 sets. Enumerating runs with jokers is also more difficult because we have to consider the placement of the joker in the set. The full number of sets is given in Table 1. In total, there are 1173 valid sets.

We then define the parameter sij which equals the number of times tile i appears in set j. This then encodes which sets are valid. To turn this into a constraint, we will require that the amount of times a tile appears in these valid sets must equal how many times this tile will appear on the board. This finally leads to the following ILP.

To give a short explanation on the constraints, note that if any set j appears xj times, we have that tile i 37 must be ∑11 sijxi times on the j=1 board. On the other hand, ti + yi gives the actual number of times tile i will be on the board. These of course have to equal each other.

The other constraint yi ≤ ri simply says that we can't play tile i more often than that we have it.

Extending the model While this model works well for us, it can be extended in multiple ways.

In the game of Rummikub the tiles have point values equal to the number on the tile. Multiple rounds are played and the points left on your rack will be added up over these rounds, where the goal is to have as little points as possible. So it is beneficial to play tiles of higher point values. To account for this, we can modify the objective of our model by weighting the variables in our objective by their point values. For more extenstions of the ILP you can again look into the aforementioned article [1].

Furthermore, this model always gives the highest number of tiles that can be played, while it can often be beneficial to withhold tiles in the actual game of Rummikub.

With­holding tiles gives fewer options to your opponents. An interesting option would be to make an AI which can decide how many tiles to play.

Implementation and examples I implemented the model of Equation (2) in Python using the software package Gurobi. In Gurobi it is very easy to implement the objective, variables and constraints of our model and it can also solve the ILP for us. The solver obtained the solution very fast for every instance I tried it on. The most difficult part was actually enumerating the sets, as considering every case was quite tricky.

To end this piece, I will give a few instances where I applied the model and which you can try for yourself.

In Figure 4 the model found that 3 tiles can be played from the rack, while in Figure 5 we can play 7 tiles.

You can try for yourself which tiles can be played in these cases. In conclusion, I think the game of Rummikub shows a very fun case where we can apply the knowledge we learn during our studies.

References [1] Dick Den Hertog and PB Hulshof. Solving rummikub problems by integer linear programming. The Computer Journal, 49(6):665{669, 2006.

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Christmas Dinner Recipes Text: Christmas diner committee

Bruschettas Ingredients (for 2 slices): • 2 slices of a baguette • 60 grams of tomatoes • 2/3 clove of garlic • 1 leaf of fresh basil • Olive oil • Balsamic vinegar • Salt • Pepper You can also use a toaster or pan to toast/grill the baguette slices Oven: 1. Preheat the oven at 200° C. 2. Cut the baguette in oblique slices.

3. Whenever the oven is done preheating, you can put the slices in the oven.

4. Bake them for 2-5 minutes until they are nicely browned.

Tomato mixture: 1. Cut the tomatoes, garlic and basil into small pieces and put them into a bowl.

2. Put some olive oil and balsamic vinegar over the tomatoes.

3. Add some salt and pepper to the mixture to perfect the taste.

• fresh basil (1 leaf per roll) • some olive oil Steps: 1. Cut the eggplant into approximately 10 slices lengthwise. Ensure that none of the slices have one side of only skin. (only skin at the edges of the slices) 2. Heat up a skillet with the olive oil and bake the eggplant for around 7 minutes (until fully cooked) at medium-high heat. Make sure that each slice is fully touching the pan while baking. This step can be done in several batches depending on the size of the pan.

3. Dry the baked eggplant with some paper towels to get rid of excess oil and water.

4. Cut up the mozzarella into small pieces.

5. Slice the basil.

6. Thinly spread the pesto onto the eggplant slices.

7. Place some mozzarella and basil onto each eggplant slice, then roll up the slices.

Steps: 1. Preheat the oven to 180 degrees 2. Cut the bell pepper into halves and remove the seeds.

3. TIP: If the bell pepper cannot lie stable, cut off a thin slice of the bottom, such that it stabilizes.

4. Cut the vegetables and cheese and put them together in a bowl, first the red onion, then the zucchini and tomato.

5. Add some salt and pepper, the pesto and half of the white cheese.

6. TIP: if you have any Italian herbs (basil, oregano, thyme, rosemary) then add them too!

7. Fill the bell pepper with the veggies and cheese, add the rest of the cheese you saved earlier on too.

8. Put them into the oven for 20 minutes.

9. Serve the stuffed bell peppers with (mashed) potatoes, rice or couscous

Stuffed bell peppers

Eggplant rolls Ingredients (for 4 persons): • 2 eggplants • Some pesto • 250g mozzarella

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Ingredients (for 4 persons): • 4 pointed bell peppers • 2 red onions • 1 zucchini • 2 tomatoes • 4 tablespoons (60g) green pesto • 240 grams ‘witte kaas’ • salt and pepper

Quark dessert with strawberries and nut mix Ingredients (for 4 persons): • 90 gram crunchy oat cookies • 8 tablespoons strawberry jam • 8 (or more) strawberries • 60 gram raw nut mix • 500 gram full-fat cottage cheese

• 1 teaspoon (mild) olive oil • 1 teaspoon of cocoa powder Steps: 1. Preheat the oven to 160 degrees 2. Mix the nuts with the cocoa powder, oil and some salt in a bowl 3. Divide the nuts over a baking tray lined with baking paper and roast the nuts in the oven for 15 minutes 4. Finely chop the roasted nut mix 5. Put the oat cookies in a plastic

bag (or two) and roll them fine with the rolling pin 6. Slice the strawberries 7. Fill the glasses with the first layer of the half of oat biscuits, the half of the cottage cheese and the half of the strawberries and strawberry jam.

8. Next, do it again with the second half of the biscuits, cheese, strawberries and jam 9. Finally, sprinkle the glasses with the roasted nut mix.

Christmas Dinner Story Text: Amalie Zeraïria Do you wonder whether you could celebrate Christmas in April? The answer is yes! It is all possible here at Abacus.

This year we gathered all our creativity and organized an online Christmas dinner.

Many Abacus members used this opportunity to have a four-course dinner with wonderful company. It was a great way to see all abacus members again and have a delicious dinner, if I could say so myself.

Perhaps, some students even impressed themselves with their coo-

king skills.

As a committee, we did all that we could to provide a Christmas atmosphere during the dinner. We wrote Christmas cards and made sure everybody had some tea lights and a Christmas-themed napkin ready for the dinner. Fortunately, there were many students who did also contribute to this by putting on their nicest Christmas suits.

For the committee members, it felt like the dinner lasted multiple days. Usually, we have to clean up the kitchen together and have leftovers which are distributed naturally over some hungry students. This year, the remaining groceries were for the committee members. I myself was left with tons of tomatoes, enough for three more times bruschetta and a big pan of soup.

After all, I am already looking forThe “behind the scenes” of this din- ward to the next one. How amazing ner was different than other years. would it be to have two Christmas However, I still found myself singing dinners in one calendar year?!

‘All I want for Christmas’ during the cutting and pre-cooking.

Review: Christmas Dinner Text: Leanne van der Meer The Christmas dinner was very fun!

We got to choose from a menu some days before the actual dinner. I was very surprised at the amount of possible choices! There was something for everyone. I went with the bruschetta, then the aubergine rolls, the stuffed bell pepper and of course I had to go

with the salted caramel chocolate dome. The recipes were surprisingly easy to follow, especially with the live discord class :).

The aubergine rolls were a bit of a struggle but I managed to get them done quite successfully, if I do say so myself ( my housemates were less than impressed lol ). Of course, after eating the aubergine rolls I was already full :’( ( They were very good though ). The stuffed bell

peppers were more of bell pepper buried in stuffing (:. I definitely had enough food for multiple days.

After attempting to wait for everybody to finnish their main dish for about five minutes we decided we couldn’t possibly wait any longer to get our dessert. overall it was a very fun evening, the christmas dinner committee did so well!

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Interview: Clara Stegehuis Text: Diana Dalenoord

tical scientist.

As a little girl, did you know that you wanted to become a mathematical scientist?

Mathematical research and popularisation of mathematics wins prizes Clara was recently in the news because she was chosen as one of the 'thirty talents under thirty' in Elsevier Weekblad. Earlier, she had won prizes from the Royal Mathematical Society for her PhD work and she also received the Professor de Winter Prize. She not only focuses on her mathematical research with various applications, but she also sees passing on her knowledge as an important part of her work.

How does it feel to be honoured for your efforts in the field of applied mathematics?

"That is of course a very nice recognition! I especially like the fact that my efforts to popularise mathematics are also appreciated, and not only my research. I think it is important and also very nice to do both."

You obtained your Bachelor's and Master's degrees in Applied Mathematics at UT and then obtained your PhD at TU/e. Fortunately, you came back to work as a mathema26

"No, actually not at all. I didn't know what a scientist did anyway, let alone that I wanted to become one. I always liked maths, but many other subjects I found interesting as well, so for me, it wasn't at all clear beforehand that I would do something in maths.

When I went to university, I enrolled in the bachelor's programme in Biomedical Technology. After my final exams at secondary school, I decided to switch to Applied Mathematics because I thought mathematics would give me more options and I might be able to enter the biomedical field later if I still wanted to. I found the Applied Mathematics programme very fun and challenging, which is why I stayed in mathematics as a

scientist."

What makes mathematics so fascinating or unique that you wanted to pursue it?

"I like the fact that mathematics can be used in so many different areas. And it's also really handy that you don't need much to do maths: a computer, a pen and paper, and you can work with maths anywhere!

During my studies, the assignments were always fun. For example, I remember a project in the second year of my bachelor's degree in which we were given an assignment by a company in Enschede to research data about different layers in the ground, for example, to predict earthquakes. I found it very interesting to work with a company at the beginning of my studies. I realised then that it is quite difficult to apply what you have just learned to a problem in society. It's not just maths you have to deal with either, in this assignment knowledge of the geology of the earth was also important. I certainly found it fasci-

related to my research and all kinds of applications of it. Recently, I supervised a student who was researching network models for constellations where an answer was sought to the question of how we can mathematically understand how constellations are drawn. Now I am supervising a student who is researching epidemic models on networks of which the connections can change (e.g. due to a lockdown). It's interesting to see how such a student approaches this and how I can give my input."

What are your challenges in mathematics? nating to see how you apply what you have learned and how you can therefore have an impact on society with mathematics."

Currently, you are working as an assistant professor in the research group Discrete Mathematics and Mathematical Programming (DMMP).

What is your mathematical expertise?

"My specialisation lies in probability and network science, combined with numerical experiments.

I perform mathematical research on large networks. Applications include social media, but also the internet or networks in your brain.

Questions I find interesting include: how does a process spread across a network? I recently researched this in the area of contact research: can we calculate how much contact research during a pandemic reduces the r-value? And how does this depend on our network of social contacts?

Or: what are the small connection patterns that are most important for the functioning of such a net-

work? In networks in your body, for example, these small patterns can provide clues to the presence of mutations in your cells, but on social media, they can indicate the presence of trolls. So these are questions that also have real applications.

Mathematical research is quite abstract, because you work with models and equations, and you don't know much about the applications.

In practice, you therefore often work together with colleagues from other fields of expertise.

But I see now, for example, in the COVID pandemic, that my earlier research into epidemics is also being cited by non-mathematical researchers, which is nice to see!"

"I received a Veni grant this year, which allows me to do three years of research on a topic of my choosing. In my case, this is research into networks with 'high-dimensional geometry', which means, for example, social networks where you have a lot of information about all the members. I am going to research which small patterns in these networks can be important for the functioning of the network.

Mathematically, this will be quite a challenge, so that is what I will be working on in the coming years. I also hope to be able to participate in conferences again to discuss my research with other scientists, I'm looking forward to that!"

You are an enthusiastic mathematical scientist yourself.

How do you encourage students at UT or involve them in your research?

"I like to communicate about my research area to a wider audience through blogs, public lectures and teaching. I regularly supervise bachelor and master students, who do their final assignment on a topic

27

A Day With...

The Candidate 54th Board has been announed! We had the joy to ask the four Applied Mathematics students among them about their Candiate Board-time: Margriet Eijken, Thomas Kanger, Niels Apeldoorn and Eline Peeters Text: Daan van Kats and Lavinia Lanting

Shortly introduce yourself, and ber 1, but anything else would have anymore, you can easily just leave been fine too. without anyone noticing your future role N: My name is Niels, I am a third year double student in Physics and Mathematics and hopefully next year I will become the Chairman and the Officer of Educational Affairs of Abacus.

T: I am Thomas, I am now 19 years old, although when the Ideaal! comes out I will probably be 20, and I am the candidate Secretary and Officer of Internal Affairs of the 54th board of Abacus.

E: I'm Eline, 19 years old and when the Ideaal! comes out I will probably still be 19 years old. I am a third year Mathematics student and the candidate Treasurer of the candidate 54th board.

M: I am Margriet, candidate Officer of External Affairs. I am and will remain 21 years old for the time being and I come from Kampen

N: I wouldn't have put Educational Affairs that high, but that was because I knew that would probably be a dual function.

Who of you has the most important task and why?

N: Thomas I think, because next year we need to get members involved with Abacus again, especially freshmen and sophomores.

Organizing and planning physical activities is also an important task for the Intern. And we have to spend money, so Eline ……

E: But we also have to get money in, so Margriet is important too.

N: Yes, but we kind of already have it…..

M: But more money is always better N: I'm definitely important E: Now comes the sad moment when nobody says Niels is important.

Were these the tasks and roles you were hoping to be nominated for when you signed up? What’s it like being a candidate board in an online setting?

Why? N: So, we had all filled in a list with our favourite functions and such and this was the most ideal distribution. Eline and Margriet have their number 1 and Thomas and I have our number 1 and/or 2.

E: I basically had three positions at number one, so yes I got my num-

28

E: Still busy, but I think less busy than if it had been physically.

N: Yes, it's easier to sit in meetings and then you can just do something else in the meantime.

M: It's also easier in itself, since you now have a lot of CB announcements. When you don't feel like it

N: Glad that's an advantage M: That's an advantage and you think so too.

N: In any case, I think that with the CB dates you have more contact with the other CBs because everyone just jumps into the call online.

T: That's nice E: Nobody else has anything to do because of corona, so…

N: And what Eline also said is that it is easier to get to know the names of the other CBs because they are now always on the screen.

What’s your typical day like as a candidate board?

E: Well, you wake up, you sit at your laptop, and then meet, study, meet, study, meet and eat somewhere in between and then you go to sleep N: And in the evening sometimes a fun activity from Abacus or a CB announcement T: Read a book before going to sleep N: I have to pick that up again, the library is open again so that's possible again!

E: Your laptop will be your best friend, or your worst T: Yes, both N: And your room is getting smaller too

Do you feel like you are missing out on anything of your candi-

date board experience due to N: I don't think even if we had it, we who are all going to drink nice beer. would have said it I’m thinking about a hundred peothe current situation?

M: I think it would be nicer if it was physical, but I don't really feel like I'm missing anything right now T: I haven't really experienced a physical candidate board period, so yeah..

E: It's a shame you can't go to other people's rooms for coffee dates.

N: Anyway, it's a shame we don't go to our own Abacus room. That's something I miss.

What is the thing you are most looking forward to as a candidate board?

M: I'm looking forward to the candidate rounds, I don't know what everyone else thinks about that.

N: The change GMA E: I think I'm in the mood for that now, maybe not during the candidate rounds itself N: I think the other way around, I think meh now, but during the rounds it will probably be fun.

E: I'm looking forward to the physical activities though.

How has learning about your tasks been going thus far?

N: It's not that bad, it's now mainly a matter of sitting there in a lot of meetings, otherwise it's not that bad T: For me the meetings are not that bad, a lot of the committees don't do much yet, so I still have time to study a bit and that's going well.

Do you have things you hope to learn as a board member?

N: Speaking in public E: (laughs) So you have never spoken in public before?

N: I hope to improve that, and work with my board members E: Make nice connections with other associations.

T: Having fun

E: It's going to be fakka fakka and ple. cyan blue...

N: Really respectable if you can manage that, man

Niels, you’re a double student, but you will be Chairman. How Margriet, you will be Officer of will you ensure the superiority External Affairs. Do you already of Abacus above Arago? have a favourite partner and why?

N: By making it a much nicer association than Arago. And then I can just infiltrate there as an Arago member and see what they're doing and then I make sure we do that a little better.

M: I don't have a favorite partner, nor would it be fair to choose. I have not met everyone yet.

E: If someone wants to become Margriet's favorite partner, send an email to the Extern.

Thomas, you will be Secretary. N: But only for extra money

Do you believe that the rest of the candidate board will have Niels, you will also be Officer of anything useful to say for you Educational Affairs. Which asto take minutes of? pect of this task are you most looking forward to?

T: Probably yes N: You're way too sweet T: Should I say “you probably won’t make any sense at all”?

E: If we don't say anything useful, you don't have to take minutes...

T: Then fewer comments on the minutes, because they are going to be so good.

N: Well, if there's nothing...

Eline, you are currently the Treasurer of Linea Recta and will be the Treasurer. Has this previous experience shaped in any way your approach to your function?

E: At Linea Recta you have to do everything very manually, make your own Excel overviews and such.

At Abacus we have a really great website, just press one button and everything I ever did in my LineaRecta time is done. Respect to the www.com for that

Thomas, you will also be Officer of Internal Affairs. At least how many people can we expect you to bring to each activity?

T: When the activities will take pla-

Have you already chosen a mot- ce physically again, we're going to have a very large crowd of people to and a colour as a board?

N: I think I am most looking forward to the contact with the programme and communicating with the people involved.

What new Abacus merch can we expect to be able to buy once you are the new board?

E: If Velthuis continues at the current pace, then tea towels N: An abacus cap would be cool I think, does it already exist?

T: An Abacus chessboard N: That would be cool! Also having a special chess set built for the Abacus room.

Will you be doing any committees next year?

N: No, at least I was thinking about maybe checking out the www.com, but I'm busy with other things too T: We have already divided the emergency response officers and bartenders, so we're going to add these committees E: Me and Thomas are going to be bartenders M: And Niels and I are going to be emergency response officers

29

Following which committee are tee, sports day, Ideaal!, Twick-In M: Hopefully next year will be betyou most looking forward to? 2022, Collage committee and the ter.

M: PixCie! E: Which ones did I do again?

T: Freshmen committee seems nice N: I think the Education Committee, as Officer of Educational Affairs.

E: I think the Christmas dinner committee, because then physical version was skipped this year. Oh no wait, I should say the Ideaal!, shit.

Which committees will you be following next year?

N: I think I had the www.com, CoCo, Education committee, BataCo, Twick-In 2021, Stichting RSA and the Advisory Council.

T: I have the EEMCS trip, the freshmen committee, (A)bac(ch)us, AbActie and the (h)ERO. E: I the Christmas dinner commit-

KasCo. M: Then I have the Dies, Cantus, PixCie, Symposium and Gala committee.

What are your hopes for Abacus for the coming year?

E: Physical activities and get-toge-

Which committee that you are thers currently in will you miss the N: Especially that it no longer has to most next year? close halfway through the year.

N: I'm only in one, so it must be the NWS. T: Erik's chairmanship of the education committee is a lot of fun, so it's going to be a shame to leave it E: I always do the PromCie meeting aftertalk with Barry from InterActief at the gala committee, and that's always fun, so rip that.

M: I'm kind of staying in the PixCie, so I'm going to miss the NWS. N: There wasn't much to miss about that this year, was there?

M: Agree.

E: And that we get active first years and second years.

Any last thoughts you would like to share?

E, T: 54 'vo E: Come to the change GMA N: Does the change GMA need a minimum to approve us?

M, N, E, T: I'm looking forward to it!

Review: The Guitar Text: Timon Veurink Over 2 months between the 13th of April and the 7th of June I have practised playing the guitar and in this piece I’ll talk about all I’ve learned and what my general experience was like. Over the weeks I have bothered my housemate with a ton of questions and we practised together a couple of times as well, so huge thanks to her.

And now to the actual story, the very first time I tried playing a chord… I held the guitar, looked at my fingers and there was 1 question that went through my mind.

How are guitarists even a thing?

Considering how much my fingers hurt you’d think they all get Carpel Tunnel and stop playing. That was the moment where I decided my strategy for learning this finger hurting, madness inducing, wonderful instrument. I would practise nearly everyday a couple of times, but never more than 10 to 15 min-

30

utes, and that worked amazingly.

My first couple of weeks was pretty much just trying to let my fingers adjust to the guitar trying to get my chord transitions more smoothly.

The very first song I learned was “Riptide” by Vance Joy. It had 3 chords and was pretty challenging for me at the time, especially the chords where I had to move my entire hand were pretty hard. Then me and my housemate met up again and at that moment I set a goal for myself for what I wanted to do before I would write this piece, I wanted to play an F-chord in a song. The thing about F-chords is that they are really challenging to play, and incredibly important to become a good guitarist. The thing that makes them difficult is that you use 1 finger to press at all snares, making the guitar half a note higher. But then you also have to play an E-chord, making it an F. So each time I was done practising I would try to play and let my fingers adjust to this chord.

The next song I learned was “Let is be” by the Beatles. Wonderful song and being a 4 chord song it opened the box to many other new and interesting songs I could learn. “Let it be” also had a little bit of strumming in there which was really cool to learn. At this point it is important to mention that I was about a month and a half in at this point.

Once I finished that song, I started playing “Perfect” by Ed Sheeran.

This song really taught me a lot of different playing patterns and just fitted the 4-chord format incredibly well. I am still practising this song to this day and find it a lot of fun to play. But sadly, that is how far I got nearly 2 months. I never got the Fchord in a song, even though I did get it a couple of times when just trying it. But I still am really proud and happy that I tried playing guitar and still think I can be really happy with all the progress I’ve made.

So beware all the hot campfires in my area, there is a new guitarist in town.