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 df-sca Scalar = Slot 5
4 5nn 5 ∈ ℕ
5 2re 2 ∈ ℝ
6 2lt5 2 < 5
7 5 6 gtneii 5 ≠ 2
8 1 3 4 7 mgplem ( Scalar ‘ 𝑅 ) = ( Scalar ‘ 𝑀 )
9 2 8 eqtri 𝑆 = ( Scalar ‘ 𝑀 )