Metamath Proof Explorer


Theorem mnringscadOLD

Description: Obsolete version of mnringscad as of 1-Nov-2024. The scalar ring of a monoid ring. (Contributed by Rohan Ridenour, 14-May-2024) (New usage is discouraged.) (Proof modification is discouraged.)

Ref Expression
Hypotheses mnringscad.1 No typesetting found for |- F = ( R MndRing M ) with typecode |-
mnringscad.2 φ R U
mnringscad.3 φ M W
Assertion mnringscadOLD φ R = Scalar F

Proof

Step Hyp Ref Expression
1 mnringscad.1 Could not format F = ( R MndRing M ) : No typesetting found for |- F = ( R MndRing M ) with typecode |-
2 mnringscad.2 φ R U
3 mnringscad.3 φ M W
4 fvex Base M V
5 eqid R freeLMod Base M = R freeLMod Base M
6 5 frlmsca R U Base M V R = Scalar R freeLMod Base M
7 2 4 6 sylancl φ R = Scalar R freeLMod Base M
8 df-sca Scalar = Slot 5
9 5nn 5
10 3re 3
11 3lt5 3 < 5
12 10 11 gtneii 5 3
13 mulrndx ndx = 3
14 12 13 neeqtrri 5 ndx
15 eqid Base M = Base M
16 1 8 9 14 15 5 2 3 mnringnmulrdOLD φ Scalar R freeLMod Base M = Scalar F
17 7 16 eqtrd φ R = Scalar F