Metamath Proof Explorer


Theorem htpycn

Description: A homotopy is a continuous function. (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
Assertion htpycn ⊢ φ → F J Htpy K G ⊆ J × t II Cn K

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 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
5 simpl ⊢ h ∈ J × t II Cn K ∧ ∀ s ∈ X s h 0 = F ⁡ s ∧ s h 1 = G ⁡ s → h ∈ J × t II Cn K
6 4 5 biimtrdi ⊢ φ → h ∈ F J Htpy K G → h ∈ J × t II Cn K
7 6 ssrdv ⊢ φ → F J Htpy K G ⊆ J × t II Cn K