Perm.perm_trans: def of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/perm.bend as Perm
Lines 44-50 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=44&end_line=50

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

# Permutation is transitive.
def perm_trans(-A: Data, +xs: List<&2, A>, -ys: List<&2, A>, -zs: List<&2, A>, h1: K.perm(A, xs, ys), h2: K.perm(A, ys, zs)) -> K.perm(A, xs, zs):
  (s1, e1) = h1
  (s2, e2) = h2
  +s1 = s1
  +s2 = s2
  (List.append(&2, Nat, s1, s2), internal_trans_eq(A, s1, s2, xs, ys, zs, e1, e2))

Uses (6):
  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=Nat
  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_trans_eq
  https://jend.leeeet.dev/definition.txt?path=bendlib-kernel-list@1.0.0.0/list.bend&name=perm