Metamath Proof Explorer


Theorem cnambpcma

Description: ((a-b)+c)-a = c-a holds for complex numbers a,b,c. (Contributed by Alexander van der Vekens, 23-Mar-2018)

Ref Expression
Assertion cnambpcma ABCAB+C-A=CB

Proof

Step Hyp Ref Expression
1 subcl ABAB
2 1 3adant3 ABCAB
3 simp3 ABCC
4 simp1 ABCA
5 2 3 4 addsubd ABCAB+C-A=AB-A+C
6 simpl ABA
7 simpr ABB
8 6 7 6 3jca ABABA
9 8 3adant3 ABCABA
10 sub32 ABAA-B-A=A-A-B
11 9 10 syl ABCA-B-A=A-A-B
12 11 oveq1d ABCAB-A+C=AA-B+C
13 subcl AAAA
14 13 anidms AAA
15 14 3ad2ant1 ABCAA
16 simp2 ABCB
17 15 16 3 subadd23d ABCAA-B+C=AA+C-B
18 subid AAA=0
19 18 oveq1d AAA+C-B=0+C-B
20 19 3ad2ant1 ABCAA+C-B=0+C-B
21 subcl CBCB
22 21 ancoms BCCB
23 22 addlidd BC0+C-B=CB
24 23 3adant1 ABC0+C-B=CB
25 17 20 24 3eqtrd ABCAA-B+C=CB
26 5 12 25 3eqtrd ABCAB+C-A=CB