proposition: Lemma oprod2_succ a b: ordinalp a -> ordinalp b -> a *o (osucc b) = (a *o b) +o a.
proof: Proof. move=> oa ob. rewrite -(osucc_pr ob) (oprodD ob OS1 oa); rewrite oprod1r //. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)