Metamath Proof Explorer


Theorem mgpval

Description: Value of the multiplication group operation. (Contributed by Mario Carneiro, 21-Dec-2014)

Ref Expression
Hypotheses mgpval.1 ⊢ M = mulGrp R
mgpval.2 ⊢ · ˙ = ⋅ R
Assertion mgpval ⊢ M = R sSet + ndx · ˙

Proof

Step Hyp Ref Expression
1 mgpval.1 ⊢ M = mulGrp R
2 mgpval.2 ⊢ · ˙ = ⋅ R
3 id ⊢ r = R → r = R
4 fveq2 ⊢ r = R → ⋅ r = ⋅ R
5 4 2 eqtr4di ⊢ r = R → ⋅ r = · ˙
6 5 opeq2d ⊢ r = R → + ndx ⋅ r = + ndx · ˙
7 3 6 oveq12d ⊢ r = R → r sSet + ndx ⋅ r = R sSet + ndx · ˙
8 df-mgp ⊢ mulGrp = r ∈ V ⟼ r sSet + ndx ⋅ r
9 ovex ⊢ R sSet + ndx · ˙ ∈ V
10 7 8 9 fvmpt ⊢ R ∈ V → mulGrp R = R sSet + ndx · ˙
11 fvprc ⊢ ¬ R ∈ V → mulGrp R = ∅
12 reldmsets ⊢ Rel ⁡ dom ⁡ sSet
13 12 ovprc1 ⊢ ¬ R ∈ V → R sSet + ndx · ˙ = ∅
14 11 13 eqtr4d ⊢ ¬ R ∈ V → mulGrp R = R sSet + ndx · ˙
15 10 14 pm2.61i ⊢ mulGrp R = R sSet + ndx · ˙
16 1 15 eqtri ⊢ M = R sSet + ndx · ˙