Metamath Proof Explorer


Theorem phtpyhtpy

Description: A path homotopy is a homotopy. (Contributed by Mario Carneiro, 23-Feb-2015)

Ref Expression
Hypotheses isphtpy.2 φ F II Cn J
isphtpy.3 φ G II Cn J
Assertion phtpyhtpy φ F PHtpy J G F II Htpy J G

Proof

Step Hyp Ref Expression
1 isphtpy.2 φ F II Cn J
2 isphtpy.3 φ G II Cn J
3 1 2 isphtpy φ h F PHtpy J G h F II Htpy J G s 0 1 0 h s = F 0 1 h s = F 1
4 simpl h F II Htpy J G s 0 1 0 h s = F 0 1 h s = F 1 h F II Htpy J G
5 3 4 syl6bi φ h F PHtpy J G h F II Htpy J G
6 5 ssrdv φ F PHtpy J G F II Htpy J G