2019 Crossing Numbers Workshop

May (5) 6 - 10, 2019
Telč, CZ (mid between Prague and Vienna)

         a beautiful historic town, listed by UNESCO.

Workshop venue: Masaryk University Centre in Telč (located right on this beautiful square, in a former Jesuit school).

Motto: To meet together, and study the beautiful problems dealing with various flavours of graph crossing numbers, and more generally with geometric graphs.


  • History (since 2010)
  • Participation: by invitation only (however, if we have forgotten about you, just send me an email, @ynenilhfi.muni.cz),
      The registration link has already been sent to all invited participants, please register by April 7
    (again, send me an email if you have problems with the registration).
  • Distinguished invited guests: Carsten Thomassen, Gelasio Salazar
  • Workshop steering committee: Drago Bokal, Markus Chimani, Petr Hliněný, Oswin Aichholzer, Gelasio Salazar
  • Local organizers: Alan Arroyo (IST), Onur Çağırıcı, Michał Dębski, Petr Hliněný
  • Practicalities: see below for details. Quickly, the program starts on Sunday evening and ends on Friday morning or noon (you may plan to leave early morning if it is convenient for you). All workshop except the trip will take place in the centre, only for dinners we will have to go out on the main square. But for those who want to walk around, the town is simply great.

NEW: Workshop problems summary

Alan and Michał have prepared a summary of the presented (and partly solved) problems from this year workshop - download PDF.

Some group photos of the workshop participants in Telč.


The daily routine (Monday to Friday):
  • Breakfast 7:30 - 8:30 on the ground floor (indoors, one below the main entrance level), then research.
  • Simple coffee break 10:30 on the ground floor, then research again.
  • Lunch 12:30 - 13:00 on the first floor (indoors, the main entrance level). We will post the menu here.
  • Coffee break with cakes 15:30, then research.
  • Dinner outside, individually arranged (many restaurants on the square).
  • Vacate your rooms by 9:00, and store your luggage into P2.
  • Final progress reports at 9:00 in P2 - come all. Then final research arrangements / plans in the groups.
  • Progress reports at 9:00 in P2 - come all. Then research as usual.
  • Workshop dinner - starts at 18:30 in P1 (the dungeon), but there will be plenty of food and drinks till late.
  • Workshop photo - meet during coffee break, and we will go outdoors for the photo.
  • Afternoon trip - we go by cars to Velky Parezity Rybnik (large but empty pond). Read here.
  • No organized plans for the evening, after you return from the trip.
  • Morning session - meet in P2 at 9:00, then research groups (all on the first floor).
  • Meet all from 14:15 in P2 to discuss the trip on Wednesday (take some break after lunch).
  • Afternoon sessions from 14:30 in the rooms in the first floor (not dungeon).
  • No organized plans for the evening - arrange dinner and possible more research as you like.
  • Opening session from 9:00 in P1 (the historic lecture room on the ground floor). Get to know your fellow participants, and what they are working on. Decide what problems to work on during the week.
  • Monday evening beer tasting (after dinner, no food except beers) - from 20:00 in P1.
Sunday arrival

Nothing formal is planned on Sunday (arrival), but we will informally gather together for dinner outside, for discussions, etc, just walk around in the Centre to meet each other. The reception in the centre will be open since 16:00 (enter through an old door by the church, just across the street from the entry to the castle, Google map).

Sunday dinner - meet around 19:00 in the corridor of the main entrance.

Other special arrangements
  • Wednesday afternoon organized hiking trip (of various levels of difficulty), or individual sightseeing in Telč. Take normal hiking wear and shoes, no rugged terrain there. No afternoon coffee break on Wednesday.
  • Thursday organized workshop dinner with plenty of food and drinks.
  • Friday - leave your rooms by 9:00, no coffee break and early lunch since 11:00, then departure.


While the workshop venue is a beautiful and peaceful place, it is also not so easy to reach. Here is a description of what means and options of transportation you may use and expect on your journey to Telč.

  • By car: either arrive directly, or rent a car in Prague or Vienna if coming by air (either city is equally far, about 2+ hours drive). Let us know if you have a free seat so that we may possibly organize informal car sharing. Read also about parking information (simply: either free, or close).
  • By public transport: definitely use BUS (while there is a small train station in Telč, do not try a train). All the listed buses are local and they do not need advance reservation (but reservation is possible), people usually get on the bus and buy tickets there (of course, with cash CZK). We will send somebody to wait at the afternoon/evening buses, to take you to the centre.
    • Direct buses Brno → Telč (1:50 hours): Sunday (5.5.) 8:45, 11:30, 16:30, 19:30. Look here at a screenshot of the reservation site.
    • Direct buses Telč → Brno: Friday (10.5.) 5:00, 11:05, 17:15
    • Direct buses Prague → Telč (2:45 hours): Sunday (5.5.) 10:30, 16:00, 18:10, 20:10 (from the central bus terminal in Prague). Look here at a screenshot of the reservation site.
    • Direct buses Telč → Prague: Friday (10.5.) 5:45, 12:00.
    • If coming through Vienna, then go first to Brno (by train, it is convenient to travel from the airport to Brno with 1 change at Vienna main station). In Brno, beware that the main train station is under construction, and your train will stop at a crazy place called Brno dolni nadrazi, which is actually right next to the central bus terminal in Brno (easy walking distance).
  • Airport shuttle?? This is theoretically possible (easier from Prague), but the prices seem so high that you should not consider it unless you form a group coming together. Let us know if you plan to organize such a group.


Masaryk University Centre Telč -- see detailed description

We expect the participants to come on Sunday (May 5), and start the research program right on Monday morning, till Friday (May 10) morning closing session. If you tell us in advance, you may come to the centre already since Friday (May 3) or Saturday, and enjoy the town (there will be no organized activities before Sunday evening). However, we must all vacate the accommodation on Friday morning since there will be another group right after us.

We will also rent one large lecture room, and around 2 small classrooms for discussions. Besides those, there is indoor and outdoor seating in the centre and in the adjacent park. And the internet connection will be excellent (but do not forget to have Eduroam from your university!).

We plan to occupy the 22 available rooms as single or double (not more), but keep in mind that a single person pays as much as two with double occupancy. Double prices per person per night: 20 or 25 Eur. You will pay on spot, by cash (CZK) or card to the Centre. Note that we may accommodate two families (4 and 5 persons) there. (Alternatively, you may book one of the surrounding hotels yourself, but we prefer to stay together at the workshop, right?)

Concerning meals, we will likely have breakfasts and lunches together in the centre (paid separately from the accommodation, with receipt), and dinners individually in the town (on the beautiful square). The offer is breakfast+lunch+2*coffee = 16Eur per day, plus another 25Eur for one official conference dinner with some drinks. You will pay me for the organized catering, only by cash (CZK or EUR). In addition to the conference dinner, I will privately sponsor a beer-tasting evening.

We will organize some half-day trip during the week, and participants will be free to visit the many touristic attractions in the town when they like.

Looking forward to see you in Telč in May...