proposition: Lemma inverse_cone_to_limit : forall a b c, is_limit a -> is_limit b -> socle a = socle b -> cone_target a = c -> inverse c (cone_to_limit a b) = cone_to_limit b a.
proof: Proof. ir. cp (are_inverse_cone_to_limit H H0 H1 H2). app inverse_eq. Qed.
imports: Arith nat_trans