fact: Definition tail (vecsn : Vector X (S n)) : Vector X n := vecsn ∘ dni (0,, natgthsn0 n).
imports: UniMath.Combinatorics.FiniteSets UniMath.Combinatorics.Lists UniMath.Combinatorics.Vectors UniMath.MoreFoundations.PartA UniMath.MoreFoundations.Tactics