Sort.internal_length_zero: def of bend-mathlib@0.8.1.0
Import: import bend-mathlib@0.8.1.0/sort.bend as Sort
Lines 175-180 of bend-mathlib@0.8.1.0/sort.bend: https://jend.leeeet.dev/read.txt?path=bend-mathlib@0.8.1.0/sort.bend&start_line=175&end_line=180

import Base
import bend-mathlib@0.8.1.0/nat.bend as MNat

def internal_length_zero(~A: Data, +xs: List<&2, A>, e: {List.length(&2, A, xs) == 0n : Nat}) -> {xs == Nil{} : List<&2, A>}:
  match xs:
    case Nil{}:
      {==}
    case +x <> +t:
      Empty.absurd({x <> t == Nil{} : List<&2, A>}, MNat.zero_ne_succ(List.length(&2, A, t), Equal.sym(Nat, List.length(&2, A, x <> t), 0n, e)))

Uses (6):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Empty.absurd
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.sym
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.length
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=bend-mathlib@0.8.1.0/nat.bend&name=zero_ne_succ