String.internal_append_nil: def of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/string.bend as String
Lines 11-17 of bend-mathlib@0.8.1.0/string.bend: https://jend.leeeet.dev/read.txt?path=bend-mathlib@0.8.1.0/string.bend&start_line=11&end_line=17

import Base

def internal_append_nil(a: String) -> {a == String.append(a, SNil{}) : String}:
  match a:
    case SNil{}:
      {==}
    case SCon{+h, +t}:
      %internal_append_nil(t) : {SCon{h, t} == SCon{h, _} : String}
      {==}

Uses (2):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.append