101st Peripatetic Seminar on Sheaves and Logic

September 16th-17th, 2017

University of Leeds

Picture of University of


  • PSSL 101. The 101st Peripatetic Seminar on Sheaves and Logic (PSSL 101) will be held on the weekend of Saturday 16th and Sunday 17th 2017 at the School of Mathematics, University of Leeds. Following the tradition of the PSSL, this is intended to be an informal meeting, covering all areas of category theory and its applications. Talks by PhD students and young researchers are particularly encouraged. For a history of the PSSL, please see here.
  • Pre-PSSL lectures. There will be two lectures in the afternoon of Friday 15th September (14:30-15:30 and 16:00-17:00) to be given by Jiri Rosicky and Andrew Brooke-Taylor, on connections between locally presentable categories, set theory, and model theory. 


Click on a title to see the abstract of the talk, or see this page for the complete list.

Friday 15th September (pre-PSSL lectures)

School of Mathematics, Rooms 8.01 & 8.02 (MALL)

Rosický - Internal sizes in accessible categories
Coffee break  (Reading Room - Room 9.31)
Brooke-Taylor - Powerful Images for Abstract Elementary Classes

Saturday 16th September

School of Mathematics, Rooms 8.01 & 8.02 (MALL

Johnstone - Anti-Boolean toposes and infinitesimal generation
van den Berg - Univalent polymorphism
Hazratpour - Fibrations of toposes (slides)
Coffee break (Reading Room - Room 9.31)
Rosický - Barely locally presentable categories  (slides)
Espindola - Stone duality for infinitary first-order logic (slides)
Di Liberti - Weak saturation and weak amalgamation property (slides)
12:30-14:00 Lunch break
Adámek - Codensity monads and density comonads of set functors
Ghiorzi - Internal enriched categories
15:00-15:30 Taylor - Bimonoidal adjunctions (slides)
15:30-16:00 Coffee break (Reading Room - Room 9.31)
16:00-16:30 Koslowski - Augmenting graphs with memory: categorical models for (2)PDAs and generalised context-free grammars
16:30-17:00 Hines - A diagrammatic calculus for cryptographic protocols (slides)
17:00-17:30 Townsend - Hilsum-Skandalis maps in a cartesian category

Sunday 17th September

School of Mathematics,
Rooms 8.01 & 8.02 (MALL)

Verity - Generator notions in \infty-cosmology
Corner - Fubini for codescent objects
Verdon - Coherence for symmetric and braided pseudomonoids (slides)
Coffee break  (Reading Room - Room 9.31)
Goedecke - Hopf formulae for Tor
11:30-12:00 Blechschmidt - Using the internal language of toposes in commutative algebra (slides)
12:00-12:30 Patta - A categorical perspective on Entropy and a categorification of topological semimodules (slides)
Lunch break (Reading Room - Room 9.31)
Bourke - Equipping weak equivalences with algebraic structure
14:00-14:30 Swan - Lifting problems in a Grothendieck fibration (slides)
14:30-15:00 Charalambous - On Galois and Tannakian categories (slides)
15:00-15:30 Coffee break (Reading Room - Room 9.31)
15:30-16:00 Faber - Toposes of  finitely supported M-Sets
16:30-17:00 Weinberger - Interpreting type theory in appropriate presheaf toposes (slides)
16:30-17:00 Kraus - (n,1)-categories in univalent type theory

Abstracts of talks

See here.


  1. Jiří Adámek (Braunschweig)
  2. Ingo Blechschmidt (Augsburg)
  3. Benno van den Berg (Amsterdam)
  4. Andrew Brooke-Taylor (Leeds)
  5. John Bourke (Macquarie)
  6. Nigel Burke (Cambridge)
  7. Paolo Capriotti (Nottingham)
  8. Gianpietro Colato (Louvain)
  9. Georgios Charalambous (Cambridge)
  10. Alex Corner (Sheffield Hallam)
  11. Antonin Delpeuch (Oxford)
  12. Ivan Di Liberti (Masaryk)
  13. Christian Espindola
  14. Eric Faber (Cambridge)
  15. Yuning Feng (Birmingham)
  16. Cesare Gallozzi (Leeds)
  17. Nicola Gambino (Leeds)
  18. Enrico Ghiorzi (Cambridge)
  19. Julia Goedecke (Leicester)
  20. Marino Gran (Louvain)
  21. Sina Hazratpour (Birmingham)
  22. Peter Hines (York)
  23. Martin Hyland (Cambridge)
  24. Peter Johnstone (Cambridge)
  25. Jürgen Koslowski (Braunschweig)
  26. Nicolai Kraus (Nottingham)
  27. Marco Larrea-Schiavon (Leeds)
  28. Richard Matthews (Leeds)
  29. Sean Moss (Cambridge)
  30. Jaap van Oosten (Utrecht)
  31. Simona Paoli (Leicester)
  32. Vaia Patta (Oxford)
  33. Gun Pinyo (Nottingham)
  34. Jiří Rosický (Masaryk)
  35. Andrew Smith (Leicester)
  36. Raffael Stenzel (Leeds)
  37. Andrew Swan (Amsterdam)
  38. Paul Taylor (Birmingham)
  39. Christopher Townsend
  40. Joost van Dijk (Amsterdam)
  41. Dominic Verdon (Oxford)
  42. Dominic Verity (Macquarie)
  43. Jakob Vidmar (Leeds)
  44. Jonathan Weinberger (Darmstadt)
  45. Octavio Zapata (University College London)

Equivalence statue

Travelling to Leeds

  • By plane: you can fly to either Leeds-Bradford Airport (LBA) or Manchester Airport (MAN).
    • From Leeds Bradford Airport, you can either take a taxi or bus line 757, which leaves in front of the airport and goes to Leeds Train Station.
    • From Manchester Airport, there are frequent trains from Manchester Airport to Leeds Train Station (either direct or via Manchester Piccadilly). The journey takes approximatively 75 minutes.
  • By train: you can travel to Leeds Train Station (LDS). Please consult National Rail Enquiries Website and Transpennine Express for details. 
  • By car: please see the instructions here. If you wish to park on campus, it is necessary to contact us well in advance, since all parking must be pre-booked by a member of staff. 

Arriving at the University of Leeds

  • Directions to the University of Leeds can be dowloaded from this link.
  • Walking directions from Leeds Train Station can be found here.
  • A campus map can be downloaded from this link.


All lectures, including the pre-PSSL lectures, will be in the MALL (Rooms 8.01 & 8.02) on level 8 of the School of Mathematics.

Coffee breaks

Coffee breaks will be in the Reading Room (Room 9.31) on level 9 of the School of Mathematics.


  • For lunch on Saturday, please see this link for a list and a map of coffee bars and restaurants around or near the campus of the University of Leeds which will be open on Saturday.
  • For lunch on Sunday, there will be a buffet lunch in the Reading Room (Room 9.31) on level 9 of the School of Mathematics.

Social dinner

The social dinner will be at the Red Chilli restaurant at 7pm on Saturday 16th September. The address of the restaurant is 6 Great George Street, Leeds, LS1 3DW.


There are various hotels nearby where you can book accommodation on your own, e.g.:

Cheaper alternatives include the following:

Registration and submission of talks

  • There is no registration fee. To register and submit a talk, please download the form below:

Registration Form

and return it by email to n.gambino AT leeds.ac.uk by Friday 1st September 2017

Organizing committee

  • Andrew Brooke-Taylor (Leeds)
  • Nicola Gambino (Leeds)
  • Peter Johnstone (Cambridge)

This page was last modified on January 9th, 2018 by Nicola Gambino