CoRN.model.groups.Qgroup
Example of a group: ⟨Q,[+]⟩
The rational numbers with addition form a group. The inverse function is taking the opposite.Lemma Q_is_CGroup : is_CGroup Q_as_CMonoid Qopp_is_fun.
Proof. split. apply Qplus_opp_r. simpl. rewrite Qplus_comm. apply Qplus_opp_r. Qed.
Definition Q_as_CGroup := Build_CGroup Q_as_CMonoid Qopp_is_fun Q_is_CGroup.
Canonical Structure Q_as_CGroup.