Metamath Proof Explorer


Theorem cxpsub

Description: Exponent subtraction law for complex exponentiation. (Contributed by Mario Carneiro, 22-Sep-2014)

Ref Expression
Assertion cxpsub A A 0 B C A B C = A B A C

Proof

Step Hyp Ref Expression
1 negcl C C
2 cxpadd A A 0 B C A B + C = A B A C
3 1 2 syl3an3 A A 0 B C A B + C = A B A C
4 simp2 A A 0 B C B
5 simp3 A A 0 B C C
6 4 5 negsubd A A 0 B C B + C = B C
7 6 oveq2d A A 0 B C A B + C = A B C
8 simp1l A A 0 B C A
9 simp1r A A 0 B C A 0
10 cxpneg A A 0 C A C = 1 A C
11 8 9 5 10 syl3anc A A 0 B C A C = 1 A C
12 11 oveq2d A A 0 B C A B A C = A B 1 A C
13 cxpcl A B A B
14 8 4 13 syl2anc A A 0 B C A B
15 cxpcl A C A C
16 8 5 15 syl2anc A A 0 B C A C
17 cxpne0 A A 0 C A C 0
18 8 9 5 17 syl3anc A A 0 B C A C 0
19 14 16 18 divrecd A A 0 B C A B A C = A B 1 A C
20 12 19 eqtr4d A A 0 B C A B A C = A B A C
21 3 7 20 3eqtr3d A A 0 B C A B C = A B A C