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15 July disjoint work with 2020 Evan Cavallo / Carlo Angiuli - PowerPoint PPT Presentation

ICMS 15 July disjoint work with 2020 Evan Cavallo / Carlo Angiuli Anders Mrtberg / Andrea Vezzosi Favonia floor wall floor wall wall floor comp wall wall floor cubes +) composition cubical TT major difficulty: composition


  1. ICMS 15 July disjoint work with 2020 Evan Cavallo / Carlo Angiuli Anders Mörtberg / Andrea Vezzosi Favonia

  2. floor

  3. wall floor

  4. wall wall floor

  5. comp wall wall floor

  6. cubes +) composition cubical TT major difficulty: composition for univalent universes

  7. null compositions = no walls

  8. Brunerie's number a program that should output 2* *read Guillaume Brunerie's thesis

  9. (p = (<i> <j> <k> ((test0To4 @ j) @ k) @ i))))), i = 1))))))))))))))))))))))))))))))))))))))))))) ))) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) []) 2019.03.04-cubicaltt-fbdb422ada0287dbfc7b097c4a9355ed501be6e6-stack-lts9.5-brunerie2-brunerie_opt-2.output.gz

  10. nullable compositions

  11. nullable not covering every corner not “true” under double negation not “true” under some closed substitutions

  12. kill nullable compositions!

  13. Plan A reduces to floor if null?

  14. Plan A reduces to floor if null? difficult with univalence keyword: regularity

  15. Plan B ban nullable compositions?

  16. Plan B ban nullable compositions? but universes need them in current constructions

  17. Plan C a different composition based on non-nullable ones with a different set of equations to avoid regularity

  18. Plan C a different composition based on non-nullable ones with a different set of equations to avoid regularity method 1: decision tree method 2: reflection no general construction yet

  19. cofibrations

  20. method 1: decision tree

  21. method 1: decision tree

  22. method 1: decision tree

  23. method 1: decision tree reduced reduced

  24. method 1: decision tree neocomp See [AFH] and/or Carlo's thesis

  25. method 1: decision tree neocomp comp neocomp comp comp neocomp See [AFH] and/or Carlo's thesis

  26. method 1: decision tree neocomp comp neocomp comp comp neocomp neocomp See [AFH] and/or Carlo's thesis

  27. method 1: decision tree neocomp limitation: the way/order to check dimension expressions needs to respect all equalities (e.g., subst.)

  28. method 1: decision tree variants of [AFH]-style composition D removal of duplicate walls I removal of inconsistent walls P permutation of walls S symmetry of wall constraints σ symmetry for non-diagonals only

  29. method 1: decision tree variants of [AFH]-style composition D removal of duplicate walls I removal of inconsistent walls P permutation of walls S symmetry of wall constraints σ symmetry for non-diagonals only unsolved cases: -P+S (no permutation, but with symmetry)

  30. method 1: decision tree [AFH]-style + conjunctions

  31. method 1: decision tree [AFH]-style + conjunctions trickier with +I how about

  32. method 1: decision tree [AFH]-style + conjunctions trickier with +I how about solved case by case [AFH], research notes, ...

  33. method 2: reflection [CCHM]-style composition

  34. method 2: reflection [CCHM]-style composition make intervals richer so that is surjective

  35. method 2: reflection neocomp

  36. method 2: reflection neocomp comp

  37. method 2: reflection neocomp comp used in Cubical Agda

  38. Plan C a different composition based on non-nullable ones with a different set of equations to avoid regularity but, is it worth it?

  39. none works for unknown cofibrations

  40. none works for unknown cofibrations def mycom/fun (A : 𝕁 → type) (B : 𝕁 → type) (com/A : (r : 𝕁 ) ( φ : 𝔾 ) (p : (i : 𝕁 ) (_ : [i=r ∨ φ ] (com/B : (r : 𝕁 ) ( φ : 𝔾 ) (p : (i : 𝕁 ) (_ : [i=r ∨ φ ] (r : 𝕁 ) ( φ : 𝔾 ) (p : (i : 𝕁 ) (_ : [i=r ∨ φ ]) (_ : A we can quantify over cofibrations in cooltt no known way to kill nullable compositions

  41. general theory?

  42. general theory? build univalent Kan universes with only these cofibrations still very open

  43. further reading [Angiuli] thesis Computational Semantics of Cartesian Cubical Type Theory [VMA] Cubical Agda: a dependently typed programming language with univalence and higher inductive types

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