Practical info about thematic month on Discrete Mathematics & Computer Science

Table of Contents

Here is some information to the participants

(29/01/2024 - 01/03/2024).

The weather is quite fine (some days, Mistral wind can still be strong).

1. CIRM accomodation

For those who didn't: final registration is done by booking at the following links: school GAGTA CSyDySi RIC CoW. For any question, change on the meals or nights, accompanying people: your preferred contact is

1.1. Arrival

You can arrive at CIRM at any time (even if some e-mails from CIRM say the contrary); if your arrival time is outside the reception opening time (e.g. between 17h and 21h on sundays), you should tell them, so that your key wait for you in an enveloppe. A cold dinner should be waiting for you until 21h45. If you do not count on it, please warn

1.2. Departure

Unfortunately, you cannot stay later than Saturday march 2nd.

1.3. Paying

If you were not told that our sponsors (or partner project) cover the price of your accomodation, then you should pay at the reception, by credit card, cash, for example on tuesday, just after the meal.

1.4. Special diets

If you have any special diet, please make sure that your badge has a sticker on it (allowing the restaurant staff to know your diet). If not, please go to the reception and tell them your diet so they can provide you the sticker with the right color (vegetarians should make precise whether they eat fish or not: "végé" may have ambiguous definitions depending on who you are speaking to).

1.5. Week-ends

The covered meals for saturday noon, saturday night, sunday noon consist in basic cold picnics (2 sandwiches + 1 fruit), stored in the fridge at the break room in the main CIRM building (next to the couches and coffee machine), and cost 6€ (for those who pay).

Participants can also enjoy a small kitchenette (with fridges, microwave, stove) in room A019 (ground floor of Annex) to prepare their meals. There will be food ready for a self-service breakfast on Sunday morning in the same kitchen. Be aware that, unfortunately, the room is good for up to 5 people at the same time.

The closest shops are 30 minutes by foot or 10 minutes by bus (in yellow on the map). There is a big supermarket and a vegetable shop at bus stop CC Valmante, and a small "superette" and a bakery at stop le Redon (bus B1, 521). You may want to go downtown instead (see below).

1.6. Washing machine

You can use a washing machine, together with a drying machine, at the 2nd floor of the main building (Bastide) of CIRM, or at the 1st floor of the Annex building.

2. Transportation

2.1. From the train station (St Charles)

Take the metro M2 (direction Sainte Marguerite-Dromel) to Rond-Point du Prado, then bus 21jet or B1 (opposite the boulevard) to the terminus (Campus de Luminy, or Luminy PN des Calanques on week-ends, which is 200m before). The last metro leaves around 21h30 (except on friday and saturday), after which you can take a direct night bus 521 from the train station to the entrance of the campus, until officially 00h40 (bus stop just next to the bus station; precise times can be found here, but careful that night buses can be up to 10 minutes ahead of their official times!).

The total time is about 45 minutes (plan more if the time is sharp), and the two-way ticket costs 3,40€ from the machine in metro or tramway stations, as well as some bus stops like Luminy Université. If you stay several weeks and plan to visit Marseille, it can be worth buying a 10-way ticket (15€). One can also buy a ticket inside the bus: 2€ for one-way.

The ticket has to be validated in both metro and bus, but during 1h the whole trip is counted only once.

2.2. From the airport (Marseille-Provence)

Take a shuttle bus to the train station (St Charles), then follow the previous indications.

The two-way ticket costs 16€ (about 100€ for taxi airport-Luminy). See the website of RTM.

2.3. WARNING: Bus perturbations 09/02, 22/02, 25/02

On certain days, bus B1 will be rerouted through the alternative route (see below), due to sports events at Stade Vélodrome. The exact times will be confirmed by RTM only a few days in advance (and we will try to transmit them here).

  • sunday 25/02: football match Marseille-Montpellier; bus lines deviated since 18h (possible perturbations a little before).

2.4. Alternative route to CIRM (when available):

Take metro M2 to Sainte Marguerite-Dromel (terminus), then bus 24, or bus B1 (when B1 is rerouted), to the terminus (Campus de Luminy, or Luminy Parc National des Calanques on week-ends, which is 200m before).

3. Enjoying Marseille

Marseille is a big and old city open to the Mediterranean sea and the Calanques national park. It seems there is no neutral opinion about Marseille 1, so you can make your own!

3.1. Map

See full screen

  • CIRM: orange
  • Calanques: blue (easy) and dark blue (difficult)
  • City: purple
  • Nearest shops : yellow

3.2. Calanques

Les Calanques are beautiful narrow fjord-like inlets typically found along a ~20km coast range at the south of Marseille. You can hike (on Wednesday afternoon or week-ends) in group with good shoes, a map, following a prepared route adapted to your habit of hiking.

It is strongly recommended not to go alone in les Calanques: it is a wild and rocky area where basic injuries can become serious if nobody is here to help you. Moreover, mobile phone signal can be very bad or nonexistent in some places.

Take into account that in february, the night sets around 18h.

Also, recall that this is a fragile area so please stay on the trails.

Some possible easy itineraries (map) :

  • Belvédère de Sugiton (accessible to any shoe, <1h) (geo:43.21391,5.44752?z=19);
  • Calanque de Sugiton (no technical difficulty but ~250m difference in altitude and good shoes needed, ~2h) (geo:43.21202,5.45388?z=19); return by the same path. An alternative (more difficult) route Tour Morgiou-Sugiton is presented below.

Other longer, more technical and/or scarier ideas around CIRM (map):

  • Calanques de Morgiou et Sugiton (Hiking shoes highly recommendend, technical sections, ~3h, at most 4h, red on the web map)
  • Mont Puget (Hiking shoes highly recommendend, technical sections, yellow on the web map), return by the same path (~3h, at most 4h) or via col de la Candelle and vire des américains (~4h, at most 5h) ;
  • Cap Morgiou et retour par les crêtes (Hiking shoes highly recommended, technical sections, about 4h to 5h, purple on the web map);
  • You can also walk to (or from) Callelongue or Cassis and use public transportation for the other way (day excursions).

Some basic maps of the sector are offered to you in the entrance of CIRM. Better maps (5 full hiking IGN maps of Calanques) can be borrowed from Victor Lutfalla (blue-haired organizer).

3.3. Downtown

Marseille is a very nice, diverse and surprising city. Please use the commonsense precautions as a tourist in a big city.

3.3.1. Walking

3.3.2. More culture

Remark: all public museums are free the first Sunday of each month, so in particular February 4th.

4. Exercise sessions at the school

Participants to the school of 29/01/2024-02/02/2024 will enjoy practical sessions of some software. Please tell us if you do not have your own laptop.

Much time can be raised if you have the software below installed before the school.

4.1. Walnut

Here are some instructions to install the software.

Here is the exercise sheet (updated), and their solutions.

4.2. Diddy

These instructions should apply to at least Linux and Windows:

  1. install Python (if you don't have it)
  2. pull or download
  3. install necessary packages with pip; the ones needed are listed in pip_installs.bat, which on Windows you can just run 2. If you see a message error: externally-managed-environment (under some Linux distributions), you can previously do

    sudo rename "s/$/\./" /usr/lib/python*/EXTERNALLY-MANAGED
  4. run

and hope that you see "All tests were successful." at the end.

To run your own scripts, run

python <your script>.diddy

Similar information can be found on the wiki.

Here's the exercise sheet, and exercise1.diddy.

4.3. Diagram groups

Here's the exercise sheet.

5. About CSyDySi week

Some influencer posted about our open problem session.



It is a scientific fact that French people who hate Marseille live in places whose football team has won fewer UEFA Champions League titles than the team of Marseille (OM). They also tend to have less sunny days and more rain annually. But correlation doesn't imply causality…


If you choose to ignore the list and install packages as needed whenever Diddy crashes on some import, do NOT install the pysat package (for satellite data), install python-sat (for SAT solving).

Author: The organizing committee

Created: 2024-02-23 ven. 14:35