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Basics/Contractible: a few more minor changes
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jdchristensen committed Oct 13, 2023
1 parent e464b20 commit bc8e9a0
Showing 1 changed file with 5 additions and 3 deletions.
8 changes: 5 additions & 3 deletions theories/Basics/Contractible.v
Original file line number Diff line number Diff line change
Expand Up @@ -17,7 +17,7 @@ Definition path_contr `{Contr A} (x y : A) : x = y
(** Any space of paths in a contractible space is contractible. *)
Global Instance contr_paths_contr `{Contr A} (x y : A) : Contr (x = y) | 10000.
Proof.
exists ((contr x)^ @ contr y).
exists (path_contr x y).
intro r; destruct r; apply concat_Vp.
Defined.

Expand Down Expand Up @@ -45,20 +45,22 @@ Defined.
Global Instance contr_basedpaths_etashort {X : Type} (x : X) : Contr (sig (@paths X x)) | 100
:= contr_basedpaths x.

(** Based path types with the second variable fixed. *)

Definition path_basedpaths' {X : Type} {x y : X} (p : y = x)
: (x;1) = (y;p) :> {z:X & z=x}.
Proof.
destruct p; reflexivity.
Defined.

Arguments path_basedpaths' {X x y} p : simpl nomatch.

Global Instance contr_basedpaths' {X : Type} (x : X) : Contr {y : X & y = x} | 100.
Proof.
refine (Build_Contr _ (x;1) _).
intros [y p]; apply path_basedpaths'.
Defined.

Arguments path_basedpaths' {X x y} p : simpl nomatch.

(** Some useful computation laws for based path spaces *)

Definition ap_pr1_path_contr_basedpaths {X : Type}
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