Metamath Proof Explorer


Theorem ablsubsub23

Description: Swap subtrahend and result of group subtraction. (Contributed by NM, 14-Dec-2007) (Revised by AV, 7-Oct-2021)

Ref Expression
Hypotheses ablsubsub23.v V=BaseG
ablsubsub23.m -˙=-G
Assertion ablsubsub23 GAbelAVBVCVA-˙B=CA-˙C=B

Proof

Step Hyp Ref Expression
1 ablsubsub23.v V=BaseG
2 ablsubsub23.m -˙=-G
3 simpl GAbelAVBVCVGAbel
4 simpr3 GAbelAVBVCVCV
5 simpr2 GAbelAVBVCVBV
6 eqid +G=+G
7 1 6 ablcom GAbelCVBVC+GB=B+GC
8 3 4 5 7 syl3anc GAbelAVBVCVC+GB=B+GC
9 8 eqeq1d GAbelAVBVCVC+GB=AB+GC=A
10 ablgrp GAbelGGrp
11 1 6 2 grpsubadd GGrpAVBVCVA-˙B=CC+GB=A
12 10 11 sylan GAbelAVBVCVA-˙B=CC+GB=A
13 3ancomb AVBVCVAVCVBV
14 13 biimpi AVBVCVAVCVBV
15 1 6 2 grpsubadd GGrpAVCVBVA-˙C=BB+GC=A
16 10 14 15 syl2an GAbelAVBVCVA-˙C=BB+GC=A
17 9 12 16 3bitr4d GAbelAVBVCVA-˙B=CA-˙C=B