Perm.perm_append_nil: def of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/perm.bend as Perm
Lines 118-120 of bend-mathlib@0.8.1.0/perm.bend: https://jend.leeeet.dev/read.txt?path=bend-mathlib@0.8.1.0/perm.bend&start_line=118&end_line=120

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

# Appending Nil is a permutation, by the empty step list.
def perm_append_nil(-A: Data, +xs: List<&2, A>) -> K.perm(A, List.append(&2, A, xs, Nil{}), xs):
  (Nil{}, internal_append_nil(A, xs))

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.append
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Sigma
  https://jend.leeeet.dev/definition.txt?path=bend-mathlib@0.8.1.0/perm.bend&name=internal_append_nil
  https://jend.leeeet.dev/definition.txt?path=bendlib-kernel-list@1.0.0.0/list.bend&name=perm