Perm.internal_invert: def of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/perm.bend as Perm
Lines 279-284 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=279&end_line=284

import Base

def internal_invert(+s: List<&2, Nat>) -> List<&2, Nat>:
  match s:
    case Nil{}:
      Nil{}
    case +i <> rest:
      List.append(&2, Nat, internal_invert(rest), i <> Nil{})

Uses (3):
  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