Fact actr_is_action : is_action 'N(A) actr.
Canonical actr_action := Action actr_is_action.
Notation "''M'" := actr_action (at level 8) : action_scope.

Lemma actNr x : {morph actr^~ x : u / - u}.
Fact actr_is_groupAction : is_groupAction setT 'M.