Metamath Proof Explorer


Theorem srgidmlem

Description: Lemma for srglidm and srgridm . (Contributed by NM, 15-Sep-2011) (Revised by Mario Carneiro, 27-Dec-2014) (Revised by Thierry Arnoux, 1-Apr-2018)

Ref Expression
Hypotheses srgidm.b
|- B = ( Base ` R )
srgidm.t
|- .x. = ( .r ` R )
srgidm.u
|- .1. = ( 1r ` R )
Assertion srgidmlem
|- ( ( R e. SRing /\ X e. B ) -> ( ( .1. .x. X ) = X /\ ( X .x. .1. ) = X ) )

Proof

Step Hyp Ref Expression
1 srgidm.b
 |-  B = ( Base ` R )
2 srgidm.t
 |-  .x. = ( .r ` R )
3 srgidm.u
 |-  .1. = ( 1r ` R )
4 eqid
 |-  ( mulGrp ` R ) = ( mulGrp ` R )
5 4 srgmgp
 |-  ( R e. SRing -> ( mulGrp ` R ) e. Mnd )
6 4 1 mgpbas
 |-  B = ( Base ` ( mulGrp ` R ) )
7 4 2 mgpplusg
 |-  .x. = ( +g ` ( mulGrp ` R ) )
8 4 3 ringidval
 |-  .1. = ( 0g ` ( mulGrp ` R ) )
9 6 7 8 mndlrid
 |-  ( ( ( mulGrp ` R ) e. Mnd /\ X e. B ) -> ( ( .1. .x. X ) = X /\ ( X .x. .1. ) = X ) )
10 5 9 sylan
 |-  ( ( R e. SRing /\ X e. B ) -> ( ( .1. .x. X ) = X /\ ( X .x. .1. ) = X ) )