Metamath Proof Explorer


Theorem divcn

Description: Complex number division is a continuous function, when the second argument is nonzero. (Contributed by Mario Carneiro, 12-Aug-2014)

Ref Expression
Hypotheses addcn.j J = TopOpen fld
divcn.k K = J 𝑡 0
Assertion divcn ÷ J × t K Cn J

Proof

Step Hyp Ref Expression
1 addcn.j J = TopOpen fld
2 divcn.k K = J 𝑡 0
3 df-div ÷ = x , y 0 ι z | y z = x
4 eldifsn y 0 y y 0
5 divval x y y 0 x y = ι z | y z = x
6 divrec x y y 0 x y = x 1 y
7 5 6 eqtr3d x y y 0 ι z | y z = x = x 1 y
8 7 3expb x y y 0 ι z | y z = x = x 1 y
9 4 8 sylan2b x y 0 ι z | y z = x = x 1 y
10 9 mpoeq3ia x , y 0 ι z | y z = x = x , y 0 x 1 y
11 3 10 eqtri ÷ = x , y 0 x 1 y
12 1 cnfldtopon J TopOn
13 12 a1i J TopOn
14 difss 0
15 resttopon J TopOn 0 J 𝑡 0 TopOn 0
16 13 14 15 sylancl J 𝑡 0 TopOn 0
17 2 16 eqeltrid K TopOn 0
18 13 17 cnmpt1st x , y 0 x J × t K Cn J
19 13 17 cnmpt2nd x , y 0 y J × t K Cn K
20 eqid z 0 1 z = z 0 1 z
21 eldifsn z 0 z z 0
22 reccl z z 0 1 z
23 21 22 sylbi z 0 1 z
24 20 23 fmpti z 0 1 z : 0
25 eqid if 1 x y 1 x y x 2 = if 1 x y 1 x y x 2
26 25 reccn2 x 0 y + u + w 0 w x < u 1 w 1 x < y
27 ovres x 0 w 0 x abs 0 × 0 w = x abs w
28 eldifi x 0 x
29 eldifi w 0 w
30 eqid abs = abs
31 30 cnmetdval x w x abs w = x w
32 abssub x w x w = w x
33 31 32 eqtrd x w x abs w = w x
34 28 29 33 syl2an x 0 w 0 x abs w = w x
35 27 34 eqtrd x 0 w 0 x abs 0 × 0 w = w x
36 35 breq1d x 0 w 0 x abs 0 × 0 w < u w x < u
37 oveq2 z = x 1 z = 1 x
38 ovex 1 x V
39 37 20 38 fvmpt x 0 z 0 1 z x = 1 x
40 oveq2 z = w 1 z = 1 w
41 ovex 1 w V
42 40 20 41 fvmpt w 0 z 0 1 z w = 1 w
43 39 42 oveqan12d x 0 w 0 z 0 1 z x abs z 0 1 z w = 1 x abs 1 w
44 eldifsn x 0 x x 0
45 reccl x x 0 1 x
46 44 45 sylbi x 0 1 x
47 eldifsn w 0 w w 0
48 reccl w w 0 1 w
49 47 48 sylbi w 0 1 w
50 30 cnmetdval 1 x 1 w 1 x abs 1 w = 1 x 1 w
51 abssub 1 x 1 w 1 x 1 w = 1 w 1 x
52 50 51 eqtrd 1 x 1 w 1 x abs 1 w = 1 w 1 x
53 46 49 52 syl2an x 0 w 0 1 x abs 1 w = 1 w 1 x
54 43 53 eqtrd x 0 w 0 z 0 1 z x abs z 0 1 z w = 1 w 1 x
55 54 breq1d x 0 w 0 z 0 1 z x abs z 0 1 z w < y 1 w 1 x < y
56 36 55 imbi12d x 0 w 0 x abs 0 × 0 w < u z 0 1 z x abs z 0 1 z w < y w x < u 1 w 1 x < y
57 56 ralbidva x 0 w 0 x abs 0 × 0 w < u z 0 1 z x abs z 0 1 z w < y w 0 w x < u 1 w 1 x < y
58 57 rexbidv x 0 u + w 0 x abs 0 × 0 w < u z 0 1 z x abs z 0 1 z w < y u + w 0 w x < u 1 w 1 x < y
59 58 adantr x 0 y + u + w 0 x abs 0 × 0 w < u z 0 1 z x abs z 0 1 z w < y u + w 0 w x < u 1 w 1 x < y
60 26 59 mpbird x 0 y + u + w 0 x abs 0 × 0 w < u z 0 1 z x abs z 0 1 z w < y
61 60 rgen2 x 0 y + u + w 0 x abs 0 × 0 w < u z 0 1 z x abs z 0 1 z w < y
62 cnxmet abs ∞Met
63 xmetres2 abs ∞Met 0 abs 0 × 0 ∞Met 0
64 62 14 63 mp2an abs 0 × 0 ∞Met 0
65 eqid abs 0 × 0 = abs 0 × 0
66 1 cnfldtopn J = MetOpen abs
67 eqid MetOpen abs 0 × 0 = MetOpen abs 0 × 0
68 65 66 67 metrest abs ∞Met 0 J 𝑡 0 = MetOpen abs 0 × 0
69 62 14 68 mp2an J 𝑡 0 = MetOpen abs 0 × 0
70 2 69 eqtri K = MetOpen abs 0 × 0
71 70 66 metcn abs 0 × 0 ∞Met 0 abs ∞Met z 0 1 z K Cn J z 0 1 z : 0 x 0 y + u + w 0 x abs 0 × 0 w < u z 0 1 z x abs z 0 1 z w < y
72 64 62 71 mp2an z 0 1 z K Cn J z 0 1 z : 0 x 0 y + u + w 0 x abs 0 × 0 w < u z 0 1 z x abs z 0 1 z w < y
73 24 61 72 mpbir2an z 0 1 z K Cn J
74 73 a1i z 0 1 z K Cn J
75 oveq2 z = y 1 z = 1 y
76 13 17 19 17 74 75 cnmpt21 x , y 0 1 y J × t K Cn J
77 1 mulcn × J × t J Cn J
78 77 a1i × J × t J Cn J
79 13 17 18 76 78 cnmpt22f x , y 0 x 1 y J × t K Cn J
80 79 mptru x , y 0 x 1 y J × t K Cn J
81 11 80 eqeltri ÷ J × t K Cn J