Lemma prefix_remove_self {A: decSet} (l: list A): prefix_remove l l = just []. Proof. revert l. apply list_ind. - apply idpath. - intros x xs IH. rewrite prefix_remove_stepeq. apply IH. Defined.
Require Import UniMath.Foundations.NaturalNumbers. Require Import UniMath.Combinatorics.Vectors.