Require MinMJ_theta. Require MinMJ_psi. Definition thpsids :N->Prop := [n:N]((theta (psi n)) = n). Definition thps'th's :A->Prop := [a:A](ms:Ms)((theta (psi' a ms)) = (theta' a ms)). (*Now the actual proof *) Lemma thpsid : ((n:N)(thpsids n))/\((a:A)(thps'th's a)). Lemma thetapsi: (n:N)((theta(psi n)) = n). Lemma thetapsi'theta': (a:A)(ms:Ms)((theta (psi' a ms)) = (theta' a ms)).