Metamath Proof Explorer


Theorem ringidmlem

Description: Lemma for ringlidm and ringridm . (Contributed by NM, 15-Sep-2011) (Revised by Mario Carneiro, 27-Dec-2014)

Ref Expression
Hypotheses ringidm.b B=BaseR
ringidm.t ·˙=R
ringidm.u 1˙=1R
Assertion ringidmlem RRingXB1˙·˙X=XX·˙1˙=X

Proof

Step Hyp Ref Expression
1 ringidm.b B=BaseR
2 ringidm.t ·˙=R
3 ringidm.u 1˙=1R
4 eqid mulGrpR=mulGrpR
5 4 ringmgp RRingmulGrpRMnd
6 4 1 mgpbas B=BasemulGrpR
7 4 2 mgpplusg ·˙=+mulGrpR
8 4 3 ringidval 1˙=0mulGrpR
9 6 7 8 mndlrid mulGrpRMndXB1˙·˙X=XX·˙1˙=X
10 5 9 sylan RRingXB1˙·˙X=XX·˙1˙=X