proposition: Lemma unKhr2 h h1 h2 : def2 (h2 :++ h) -> h1 :++ h = h2 :++ h -> h1 = h2.
proof: Proof. move: h h1 h2=>[h1 h2][h11 h12][h21 h22]; case/andP=>/= [D1 D2] [E1 E2]. by rewrite (unKhr D1 E1) (unKhr D2 E2). Qed.
imports: mathcomp(ssreflect ssrfun ssrnat div ssrbool seq) LemmaOverloading(prelude finmap ordtype) mathcomp(path eqtype) Eqdep