Metamath Proof Explorer


Theorem ishtpyd

Description: Deduction for membership in the class of homotopies. (Contributed by Mario Carneiro, 22-Feb-2015)

Ref Expression
Hypotheses ishtpy.1 φ J TopOn X
ishtpy.3 φ F J Cn K
ishtpy.4 φ G J Cn K
ishtpyd.1 φ H J × t II Cn K
ishtpyd.2 φ s X s H 0 = F s
ishtpyd.3 φ s X s H 1 = G s
Assertion ishtpyd φ H F J Htpy K G

Proof

Step Hyp Ref Expression
1 ishtpy.1 φ J TopOn X
2 ishtpy.3 φ F J Cn K
3 ishtpy.4 φ G J Cn K
4 ishtpyd.1 φ H J × t II Cn K
5 ishtpyd.2 φ s X s H 0 = F s
6 ishtpyd.3 φ s X s H 1 = G s
7 5 6 jca φ s X s H 0 = F s s H 1 = G s
8 7 ralrimiva φ s X s H 0 = F s s H 1 = G s
9 1 2 3 ishtpy φ H F J Htpy K G H J × t II Cn K s X s H 0 = F s s H 1 = G s
10 4 8 9 mpbir2and φ H F J Htpy K G