Metamath Proof Explorer


Theorem grpinvfn

Description: Functionality of the group inverse function. (Contributed by Stefan O'Rear, 21-Mar-2015)

Ref Expression
Hypotheses grpinvfn.b ⊢ B = Base G
grpinvfn.n ⊢ N = inv g ⁡ G
Assertion grpinvfn ⊢ N Fn B

Proof

Step Hyp Ref Expression
1 grpinvfn.b ⊢ B = Base G
2 grpinvfn.n ⊢ N = inv g ⁡ G
3 riotaex ⊢ ι y ∈ B | y + G x = 0 G ∈ V
4 eqid ⊢ + G = + G
5 eqid ⊢ 0 G = 0 G
6 1 4 5 2 grpinvfval ⊢ N = x ∈ B ⟼ ι y ∈ B | y + G x = 0 G
7 3 6 fnmpti ⊢ N Fn B