proposition: Lemma pfminh_pos : (pfminh > 0)%N.
proof: Proof. rewrite lt0n; apply/negP => /eqP H. by have:= minh_neg; rewrite -pfminhP H take0 height_simpl. Qed.
imports: HB(structures) mathcomp(all_ssreflect) mathcomp(div ssralg ssrint ssrnum binomial) tools combclass bintree