Metamath Proof Explorer


Theorem rmulccn

Description: Multiplication by a real constant is a continuous function. (Contributed by Thierry Arnoux, 23-May-2017) Avoid ax-mulf . (Revised by GG, 16-Mar-2025)

Ref Expression
Hypotheses rmulccn.1 J = topGen ran .
rmulccn.2 φ C
Assertion rmulccn φ x x C J Cn J

Proof

Step Hyp Ref Expression
1 rmulccn.1 J = topGen ran .
2 rmulccn.2 φ C
3 eqid TopOpen fld = TopOpen fld
4 3 cnfldtopon TopOpen fld TopOn
5 4 a1i φ TopOpen fld TopOn
6 5 cnmptid φ x x TopOpen fld Cn TopOpen fld
7 2 recnd φ C
8 5 5 7 cnmptc φ x C TopOpen fld Cn TopOpen fld
9 3 mpomulcn y , z y z TopOpen fld × t TopOpen fld Cn TopOpen fld
10 9 a1i φ y , z y z TopOpen fld × t TopOpen fld Cn TopOpen fld
11 oveq12 y = x z = C y z = x C
12 5 6 8 5 5 10 11 cnmpt12 φ x x C TopOpen fld Cn TopOpen fld
13 ax-resscn
14 unicntop = TopOpen fld
15 14 cnrest x x C TopOpen fld Cn TopOpen fld x x C TopOpen fld 𝑡 Cn TopOpen fld
16 12 13 15 sylancl φ x x C TopOpen fld 𝑡 Cn TopOpen fld
17 simpr φ x x
18 7 adantr φ x C
19 17 18 mulcld φ x x C
20 19 ralrimiva φ x x C
21 eqid x x C = x x C
22 21 fnmpt x x C x x C Fn
23 20 22 syl φ x x C Fn
24 13 a1i φ
25 23 24 fnssresd φ x x C Fn
26 simpr φ w w
27 oveq1 x = w x C = w C
28 resmpt x x C = x x C
29 13 28 ax-mp x x C = x x C
30 ovex w C V
31 27 29 30 fvmpt w x x C w = w C
32 26 31 syl φ w x x C w = w C
33 2 adantr φ w C
34 26 33 remulcld φ w w C
35 32 34 eqeltrd φ w x x C w
36 35 ralrimiva φ w x x C w
37 fnfvrnss x x C Fn w x x C w ran x x C
38 25 36 37 syl2anc φ ran x x C
39 cnrest2 TopOpen fld TopOn ran x x C x x C TopOpen fld 𝑡 Cn TopOpen fld x x C TopOpen fld 𝑡 Cn TopOpen fld 𝑡
40 4 38 24 39 mp3an2i φ x x C TopOpen fld 𝑡 Cn TopOpen fld x x C TopOpen fld 𝑡 Cn TopOpen fld 𝑡
41 16 40 mpbid φ x x C TopOpen fld 𝑡 Cn TopOpen fld 𝑡
42 3 tgioo2 topGen ran . = TopOpen fld 𝑡
43 1 42 eqtri J = TopOpen fld 𝑡
44 43 43 oveq12i J Cn J = TopOpen fld 𝑡 Cn TopOpen fld 𝑡
45 44 eqcomi TopOpen fld 𝑡 Cn TopOpen fld 𝑡 = J Cn J
46 41 29 45 3eltr3g φ x x C J Cn J