def perm_swap

bend-mathlib@0.8.1.0 · perm.bend:35

import Base
import bendlib-kernel-list@1.0.0.0/list.bend as K

35# Swapping the two leading elements is a permutation.
36def perm_swap(-A: Data, -x: A, -y: A, -t: List<&2, A>) -> K.perm(A, x <> y <> t, y <> x <> t):
37  (0n <> Nil{}, {==})