Metamath Proof Explorer


Theorem cncfmpt2f

Description: Composition of continuous functions. -cn-> analogue of cnmpt12f . (Contributed by Mario Carneiro, 3-Sep-2014)

Ref Expression
Hypotheses cncfmpt2f.1 J = TopOpen fld
cncfmpt2f.2 φ F J × t J Cn J
cncfmpt2f.3 φ x X A : X cn
cncfmpt2f.4 φ x X B : X cn
Assertion cncfmpt2f φ x X A F B : X cn

Proof

Step Hyp Ref Expression
1 cncfmpt2f.1 J = TopOpen fld
2 cncfmpt2f.2 φ F J × t J Cn J
3 cncfmpt2f.3 φ x X A : X cn
4 cncfmpt2f.4 φ x X B : X cn
5 1 cnfldtopon J TopOn
6 cncfrss x X A : X cn X
7 3 6 syl φ X
8 resttopon J TopOn X J 𝑡 X TopOn X
9 5 7 8 sylancr φ J 𝑡 X TopOn X
10 ssid
11 eqid J 𝑡 X = J 𝑡 X
12 5 toponrestid J = J 𝑡
13 1 11 12 cncfcn X X cn = J 𝑡 X Cn J
14 7 10 13 sylancl φ X cn = J 𝑡 X Cn J
15 3 14 eleqtrd φ x X A J 𝑡 X Cn J
16 4 14 eleqtrd φ x X B J 𝑡 X Cn J
17 9 15 16 2 cnmpt12f φ x X A F B J 𝑡 X Cn J
18 17 14 eleqtrrd φ x X A F B : X cn