Ltac gsimpl := autorewrite with gsimpl; try done.Definition gsimp := (mulg1 , mul1g, (invg1, @invgK), (mulgV, mulVg)).Definition gnorm := (gsimp, (mulgK, mulgKV, (mulgA, invMg))).Implicit Types A B : {set gT}.

Lemma set_invgK : involutive set_invg.