Metamath Proof Explorer


Theorem cncfmpt2ss

Description: Composition of continuous functions in a subset. (Contributed by Mario Carneiro, 17-May-2016)

Ref Expression
Hypotheses cncfmpt2ss.1 𝐽 = ( TopOpen ‘ ℂfld )
cncfmpt2ss.2 𝐹 ∈ ( ( 𝐽 ×t 𝐽 ) Cn 𝐽 )
cncfmpt2ss.3 ( 𝜑 → ( 𝑥𝑋𝐴 ) ∈ ( 𝑋cn𝑆 ) )
cncfmpt2ss.4 ( 𝜑 → ( 𝑥𝑋𝐵 ) ∈ ( 𝑋cn𝑆 ) )
cncfmpt2ss.5 𝑆 ⊆ ℂ
cncfmpt2ss.6 ( ( 𝐴𝑆𝐵𝑆 ) → ( 𝐴 𝐹 𝐵 ) ∈ 𝑆 )
Assertion cncfmpt2ss ( 𝜑 → ( 𝑥𝑋 ↦ ( 𝐴 𝐹 𝐵 ) ) ∈ ( 𝑋cn𝑆 ) )

Proof

Step Hyp Ref Expression
1 cncfmpt2ss.1 𝐽 = ( TopOpen ‘ ℂfld )
2 cncfmpt2ss.2 𝐹 ∈ ( ( 𝐽 ×t 𝐽 ) Cn 𝐽 )
3 cncfmpt2ss.3 ( 𝜑 → ( 𝑥𝑋𝐴 ) ∈ ( 𝑋cn𝑆 ) )
4 cncfmpt2ss.4 ( 𝜑 → ( 𝑥𝑋𝐵 ) ∈ ( 𝑋cn𝑆 ) )
5 cncfmpt2ss.5 𝑆 ⊆ ℂ
6 cncfmpt2ss.6 ( ( 𝐴𝑆𝐵𝑆 ) → ( 𝐴 𝐹 𝐵 ) ∈ 𝑆 )
7 cncff ( ( 𝑥𝑋𝐴 ) ∈ ( 𝑋cn𝑆 ) → ( 𝑥𝑋𝐴 ) : 𝑋𝑆 )
8 3 7 syl ( 𝜑 → ( 𝑥𝑋𝐴 ) : 𝑋𝑆 )
9 8 fvmptelrn ( ( 𝜑𝑥𝑋 ) → 𝐴𝑆 )
10 cncff ( ( 𝑥𝑋𝐵 ) ∈ ( 𝑋cn𝑆 ) → ( 𝑥𝑋𝐵 ) : 𝑋𝑆 )
11 4 10 syl ( 𝜑 → ( 𝑥𝑋𝐵 ) : 𝑋𝑆 )
12 11 fvmptelrn ( ( 𝜑𝑥𝑋 ) → 𝐵𝑆 )
13 9 12 6 syl2anc ( ( 𝜑𝑥𝑋 ) → ( 𝐴 𝐹 𝐵 ) ∈ 𝑆 )
14 13 fmpttd ( 𝜑 → ( 𝑥𝑋 ↦ ( 𝐴 𝐹 𝐵 ) ) : 𝑋𝑆 )
15 2 a1i ( 𝜑𝐹 ∈ ( ( 𝐽 ×t 𝐽 ) Cn 𝐽 ) )
16 ssid ℂ ⊆ ℂ
17 cncfss ( ( 𝑆 ⊆ ℂ ∧ ℂ ⊆ ℂ ) → ( 𝑋cn𝑆 ) ⊆ ( 𝑋cn→ ℂ ) )
18 5 16 17 mp2an ( 𝑋cn𝑆 ) ⊆ ( 𝑋cn→ ℂ )
19 18 3 sselid ( 𝜑 → ( 𝑥𝑋𝐴 ) ∈ ( 𝑋cn→ ℂ ) )
20 18 4 sselid ( 𝜑 → ( 𝑥𝑋𝐵 ) ∈ ( 𝑋cn→ ℂ ) )
21 1 15 19 20 cncfmpt2f ( 𝜑 → ( 𝑥𝑋 ↦ ( 𝐴 𝐹 𝐵 ) ) ∈ ( 𝑋cn→ ℂ ) )
22 cncffvrn ( ( 𝑆 ⊆ ℂ ∧ ( 𝑥𝑋 ↦ ( 𝐴 𝐹 𝐵 ) ) ∈ ( 𝑋cn→ ℂ ) ) → ( ( 𝑥𝑋 ↦ ( 𝐴 𝐹 𝐵 ) ) ∈ ( 𝑋cn𝑆 ) ↔ ( 𝑥𝑋 ↦ ( 𝐴 𝐹 𝐵 ) ) : 𝑋𝑆 ) )
23 5 21 22 sylancr ( 𝜑 → ( ( 𝑥𝑋 ↦ ( 𝐴 𝐹 𝐵 ) ) ∈ ( 𝑋cn𝑆 ) ↔ ( 𝑥𝑋 ↦ ( 𝐴 𝐹 𝐵 ) ) : 𝑋𝑆 ) )
24 14 23 mpbird ( 𝜑 → ( 𝑥𝑋 ↦ ( 𝐴 𝐹 𝐵 ) ) ∈ ( 𝑋cn𝑆 ) )