Metamath Proof Explorer


Theorem abl1

Description: The (smallest) structure representing atrivial abelian group. (Contributed by AV, 28-Apr-2019)

Ref Expression
Hypothesis abl1.m M=BasendxI+ndxIII
Assertion abl1 IVMAbel

Proof

Step Hyp Ref Expression
1 abl1.m M=BasendxI+ndxIII
2 1 grp1 IVMGrp
3 eqidd IVIIIII=IIIII
4 oveq1 a=IaIIIb=IIIIb
5 oveq2 a=IbIIIa=bIIII
6 4 5 eqeq12d a=IaIIIb=bIIIaIIIIb=bIIII
7 6 ralbidv a=IbIaIIIb=bIIIabIIIIIb=bIIII
8 7 ralsng IVaIbIaIIIb=bIIIabIIIIIb=bIIII
9 oveq2 b=IIIIIb=IIIII
10 oveq1 b=IbIIII=IIIII
11 9 10 eqeq12d b=IIIIIb=bIIIIIIIII=IIIII
12 11 ralsng IVbIIIIIb=bIIIIIIIII=IIIII
13 8 12 bitrd IVaIbIaIIIb=bIIIaIIIII=IIIII
14 3 13 mpbird IVaIbIaIIIb=bIIIa
15 snex IV
16 1 grpbase IVI=BaseM
17 15 16 ax-mp I=BaseM
18 snex IIIV
19 1 grpplusg IIIVIII=+M
20 18 19 ax-mp III=+M
21 17 20 isabl2 MAbelMGrpaIbIaIIIb=bIIIa
22 2 14 21 sylanbrc IVMAbel