Natural.nth0: def of bend-collections-laws-math@1.0.0.0
Import: import bend-collections-laws-math@1.0.0.0/spec/math/natural.bend as Natural
Lines 98-106 of bend-collections-laws-math@1.0.0.0/spec/math/natural.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/spec/math/natural.bend&start_line=98&end_line=106

import Base

# xs[i], or dflt past the end
def nth0(+xs: List<&2, Nat>, +i: Nat, +dflt: Nat) -> Nat:
  match xs i:
    case Nil{} i0:
      dflt
    case Con{x, t} 0n:
      x
    case Con{x, t} 1n+j:
      nth0(t, j, dflt)

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