proposition: Lemma lseg_neq xs p q h : p != q -> h \In lseg p q xs -> exists x, exists r, exists h', [/\ xs = x :: behead xs, p :-> x :+ (p .+ 1 :-> r :+ h') = h & h' \In lseg r q (behead xs)].
proof: Proof. case:xs=>[|x xs] /= H []; last by move=>y [h'][->] H1; hhauto. by move=>E; rewrite E eq_refl in H. Qed.
imports: mathcomp(ssreflect ssrbool eqtype seq ssrfun) LemmaOverloading(heaps rels hprop stmod stsep stlogR)