(* File reduced by coq-bug-finder from original input, then from 11218 lines to 438 lines, then from 434 lines to 202 lines, then from 140 lines to 94 lines *) (* coqc version trunk (September 2014) compiled on Sep 25 2014 2:53:46 with OCaml 4.01.0 coqtop version cagnode16:/afs/csail.mit.edu/u/j/jgross/coq-trunk,trunk (bec7e0914f4a7144cd4efa8ffaccc9f72dbdb790) *) Inductive paths {A : Type} (a : A) : A -> Type := idpath : paths a a. Set Implicit Arguments. Delimit Scope morphism_scope with morphism. Record PreCategory := { object :> Type ; morphism : object -> object -> Type }. Bind Scope category_scope with PreCategory. Local Open Scope morphism_scope. Record Functor (C D : PreCategory) := { object_of :> C -> D; morphism_of : forall s d, morphism C s d -> morphism D (object_of s) (object_of d) }. Set Primitive Projections. Class IsIsomorphism {C : PreCategory} {s d} (m : morphism C s d) := { morphism_inverse : morphism C d s }. Record NaturalTransformation C D (F G : Functor C D) := { components_of :> forall c, morphism D (F c) (G c) }. Unset Primitive Projections. Class Isomorphic {C : PreCategory} s d := { morphism_isomorphic :> morphism C s d; isisomorphism_isomorphic :> IsIsomorphism morphism_isomorphic }. Arguments morphism_inverse {C s d} m {_} / . Local Notation "m ^-1" := (morphism_inverse m) (at level 3, format "m '^-1'") : morphism_scope. Definition functor_category (C D : PreCategory) : PreCategory. exact (@Build_PreCategory (Functor C D) (@NaturalTransformation C D)). Defined. Local Notation "C -> D" := (functor_category C D) : category_scope. Generalizable All Variables. Definition isisomorphism_components_of `{@IsIsomorphism (C -> D) F G T} x : IsIsomorphism (T x). Proof. constructor. exact (T^-1 x). Defined. Hint Immediate isisomorphism_components_of : typeclass_instances. Goal forall (x3 x9 : PreCategory) (x12 f0 : Functor x9 x3) (x35 : @Isomorphic (@functor_category x9 x3) f0 x12) (x37 : object x9) (H3 : morphism x3 (@object_of x9 x3 f0 x37) (@object_of x9 x3 f0 x37)) (x34 : @Isomorphic (@functor_category x9 x3) x12 f0) (m : morphism x3 (x12 x37) (f0 x37) -> morphism x3 (f0 x37) (x12 x37) -> morphism x3 (f0 x37) (f0 x37)), @paths (morphism x3 (@object_of x9 x3 f0 x37) (@object_of x9 x3 f0 x37)) H3 (m (@components_of x9 x3 x12 f0 (@morphism_inverse (@functor_category x9 x3) f0 x12 (@morphism_isomorphic (@functor_category x9 x3) f0 x12 x35) (@isisomorphism_isomorphic (@functor_category x9 x3) f0 x12 x35)) x37) (@components_of x9 x3 f0 x12 (@morphism_inverse (@functor_category x9 x3) x12 f0 (@morphism_isomorphic (@functor_category x9 x3) x12 f0 x34) (@isisomorphism_isomorphic (@functor_category x9 x3) x12 f0 x34)) x37)). Unset Printing All. intros. match goal with | [ |- context[components_of ?T^-1 ?x] ] => progress let T1 := constr:(T^-1 x) in let T2 := constr:((T x)^-1) in change T1 with T2 || fail 1 "too early" end. Undo. match goal with | [ |- context[components_of ?T^-1 ?x] ] => progress let T1 := constr:(T^-1 x) in change T1 with ((T x)^-1) || fail 1 "too early 2" end. Undo. match goal with | [ |- context[components_of ?T^-1 ?x] ] => progress let T2 := constr:((T x)^-1) in change (T^-1 x) with T2 end. (* not convertible *) (* (@components_of x9 x3 x12 f0 (@morphism_inverse _ _ _ (@morphism_isomorphic (functor_category x9 x3) f0 x12 x35) _) x37) *)