Metamath Proof Explorer


Theorem oppgbas

Description: Base set of an opposite group. (Contributed by Stefan O'Rear, 26-Aug-2015)

Ref Expression
Hypotheses oppgbas.1 O = opp 𝑔 R
oppgbas.2 B = Base R
Assertion oppgbas B = Base O

Proof

Step Hyp Ref Expression
1 oppgbas.1 O = opp 𝑔 R
2 oppgbas.2 B = Base R
3 df-base Base = Slot 1
4 1nn 1
5 1ne2 1 2
6 1 3 4 5 oppglem Base R = Base O
7 2 6 eqtri B = Base O