Metamath Proof Explorer


Theorem cxpcncf1

Description: The power function on complex numbers, for fixed exponent A, is continuous. Similar to cxpcn . (Contributed by Thierry Arnoux, 20-Dec-2021)

Ref Expression
Hypotheses cxpcncf1.a φ A
cxpcncf1.d φ D −∞ 0
Assertion cxpcncf1 φ x D x A : D cn

Proof

Step Hyp Ref Expression
1 cxpcncf1.a φ A
2 cxpcncf1.d φ D −∞ 0
3 resmpt D −∞ 0 x −∞ 0 x A D = x D x A
4 2 3 syl φ x −∞ 0 x A D = x D x A
5 eqid TopOpen fld = TopOpen fld
6 5 cnfldtopon TopOpen fld TopOn
7 difss −∞ 0
8 resttopon TopOpen fld TopOn −∞ 0 TopOpen fld 𝑡 −∞ 0 TopOn −∞ 0
9 6 7 8 mp2an TopOpen fld 𝑡 −∞ 0 TopOn −∞ 0
10 9 a1i φ TopOpen fld 𝑡 −∞ 0 TopOn −∞ 0
11 10 cnmptid φ x −∞ 0 x TopOpen fld 𝑡 −∞ 0 Cn TopOpen fld 𝑡 −∞ 0
12 6 a1i φ TopOpen fld TopOn
13 10 12 1 cnmptc φ x −∞ 0 A TopOpen fld 𝑡 −∞ 0 Cn TopOpen fld
14 eqid −∞ 0 = −∞ 0
15 eqid TopOpen fld 𝑡 −∞ 0 = TopOpen fld 𝑡 −∞ 0
16 14 5 15 cxpcn y −∞ 0 , z y z TopOpen fld 𝑡 −∞ 0 × t TopOpen fld Cn TopOpen fld
17 16 a1i φ y −∞ 0 , z y z TopOpen fld 𝑡 −∞ 0 × t TopOpen fld Cn TopOpen fld
18 oveq12 y = x z = A y z = x A
19 10 11 13 10 12 17 18 cnmpt12 φ x −∞ 0 x A TopOpen fld 𝑡 −∞ 0 Cn TopOpen fld
20 ssid
21 6 toponrestid TopOpen fld = TopOpen fld 𝑡
22 5 15 21 cncfcn −∞ 0 −∞ 0 cn = TopOpen fld 𝑡 −∞ 0 Cn TopOpen fld
23 7 20 22 mp2an −∞ 0 cn = TopOpen fld 𝑡 −∞ 0 Cn TopOpen fld
24 23 eqcomi TopOpen fld 𝑡 −∞ 0 Cn TopOpen fld = −∞ 0 cn
25 24 a1i φ TopOpen fld 𝑡 −∞ 0 Cn TopOpen fld = −∞ 0 cn
26 19 25 eleqtrd φ x −∞ 0 x A : −∞ 0 cn
27 rescncf D −∞ 0 x −∞ 0 x A : −∞ 0 cn x −∞ 0 x A D : D cn
28 27 imp D −∞ 0 x −∞ 0 x A : −∞ 0 cn x −∞ 0 x A D : D cn
29 2 26 28 syl2anc φ x −∞ 0 x A D : D cn
30 4 29 eqeltrrd φ x D x A : D cn