proposition: Lemma intdomax2l (X : intdom) (x y : X) (is : paths (x * y) 0) (ne : x != 0) : y = 0.
proof: Proof. intros. set (int := intdomax X _ _ is). generalize ne. assert (int' : isaprop (x != 0 -> y = 0)). { apply impred. intro. apply (setproperty X _ _). } generalize int. simpl. apply (@hinhuniv _ (make_hProp _ int')). intro ene. destruct ene as [ e'' | ne' ]. - destruct (ne e''). - intro. apply ne'. Defined.
imports: UniMath.Algebra.Groups UniMath.Algebra.RigsAndRings