Metamath Proof Explorer


Theorem mgpsca

Description: The multiplication monoid has the same (if any) scalars as the original ring. Mostly to simplify pwsmgp . (Contributed by Mario Carneiro, 12-Mar-2015) (Revised by Mario Carneiro, 5-May-2015)

Ref Expression
Hypotheses mgpbas.1
|- M = ( mulGrp ` R )
mgpsca.s
|- S = ( Scalar ` R )
Assertion mgpsca
|- S = ( Scalar ` M )

Proof

Step Hyp Ref Expression
1 mgpbas.1
 |-  M = ( mulGrp ` R )
2 mgpsca.s
 |-  S = ( Scalar ` R )
3 eqid
 |-  ( .r ` R ) = ( .r ` R )
4 1 3 mgpval
 |-  M = ( R sSet <. ( +g ` ndx ) , ( .r ` R ) >. )
5 scaid
 |-  Scalar = Slot ( Scalar ` ndx )
6 scandxnplusgndx
 |-  ( Scalar ` ndx ) =/= ( +g ` ndx )
7 4 5 6 setsplusg
 |-  ( Scalar ` R ) = ( Scalar ` M )
8 2 7 eqtri
 |-  S = ( Scalar ` M )