Metamath Proof Explorer


Theorem htpycn

Description: A homotopy is a continuous function. (Contributed by Mario Carneiro, 22-Feb-2015)

Ref Expression
Hypotheses ishtpy.1 ( 𝜑𝐽 ∈ ( TopOn ‘ 𝑋 ) )
ishtpy.3 ( 𝜑𝐹 ∈ ( 𝐽 Cn 𝐾 ) )
ishtpy.4 ( 𝜑𝐺 ∈ ( 𝐽 Cn 𝐾 ) )
Assertion htpycn ( 𝜑 → ( 𝐹 ( 𝐽 Htpy 𝐾 ) 𝐺 ) ⊆ ( ( 𝐽 ×t II ) Cn 𝐾 ) )

Proof

Step Hyp Ref Expression
1 ishtpy.1 ( 𝜑𝐽 ∈ ( TopOn ‘ 𝑋 ) )
2 ishtpy.3 ( 𝜑𝐹 ∈ ( 𝐽 Cn 𝐾 ) )
3 ishtpy.4 ( 𝜑𝐺 ∈ ( 𝐽 Cn 𝐾 ) )
4 1 2 3 ishtpy ( 𝜑 → ( ∈ ( 𝐹 ( 𝐽 Htpy 𝐾 ) 𝐺 ) ↔ ( ∈ ( ( 𝐽 ×t II ) Cn 𝐾 ) ∧ ∀ 𝑠𝑋 ( ( 𝑠 0 ) = ( 𝐹𝑠 ) ∧ ( 𝑠 1 ) = ( 𝐺𝑠 ) ) ) ) )
5 simpl ( ( ∈ ( ( 𝐽 ×t II ) Cn 𝐾 ) ∧ ∀ 𝑠𝑋 ( ( 𝑠 0 ) = ( 𝐹𝑠 ) ∧ ( 𝑠 1 ) = ( 𝐺𝑠 ) ) ) → ∈ ( ( 𝐽 ×t II ) Cn 𝐾 ) )
6 4 5 syl6bi ( 𝜑 → ( ∈ ( 𝐹 ( 𝐽 Htpy 𝐾 ) 𝐺 ) → ∈ ( ( 𝐽 ×t II ) Cn 𝐾 ) ) )
7 6 ssrdv ( 𝜑 → ( 𝐹 ( 𝐽 Htpy 𝐾 ) 𝐺 ) ⊆ ( ( 𝐽 ×t II ) Cn 𝐾 ) )