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 ( .r𝑅 ) = ( .r𝑅 )
4 1 3 mgpval 𝑀 = ( 𝑅 sSet ⟨ ( +g ‘ ndx ) , ( .r𝑅 ) ⟩ )
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 )