Metamath Proof Explorer


Theorem mnringbased

Description: The base set of a monoid ring. (Contributed by Rohan Ridenour, 14-May-2024) (Proof shortened by AV, 1-Nov-2024)

Ref Expression
Hypotheses mnringbased.1 ⊢ F = R MndRing M
mnringbased.2 ⊢ A = Base M
mnringbased.3 ⊢ V = R freeLMod A
mnringbased.4 ⊢ B = Base V
mnringbased.5 ⊢ φ → R ∈ U
mnringbased.6 ⊢ φ → M ∈ W
Assertion mnringbased ⊢ φ → B = Base F

Proof

Step Hyp Ref Expression
1 mnringbased.1 ⊢ F = R MndRing M
2 mnringbased.2 ⊢ A = Base M
3 mnringbased.3 ⊢ V = R freeLMod A
4 mnringbased.4 ⊢ B = Base V
5 mnringbased.5 ⊢ φ → R ∈ U
6 mnringbased.6 ⊢ φ → M ∈ W
7 baseid ⊢ Base = Slot Base ndx
8 basendxnmulrndx ⊢ Base ndx ≠ ⋅ ndx
9 1 7 8 2 3 5 6 mnringnmulrd ⊢ φ → Base V = Base F
10 4 9 eqtrid ⊢ φ → B = Base F