lemma eq_to_eq': ∀o1,o2.∀r,r': relation_pair_setoid o1 o2. r=r' → r \sub\f ∘ ⊩ = r'\sub\f ∘ ⊩.
intros 5 (o1 o2 r r' H); change in H with (⊩ ∘ r\sub\c = ⊩ ∘ r'\sub\c);
- apply (.= (commute ?? r \sup -1));
+ apply (.= ((commute ?? r) \sup -1));
apply (.= H);
apply (.= (commute ?? r'));
apply refl1;