Defs.first: def of lawful-bytes@0.1.1.0
Import: import lawful-bytes@0.1.1.0/defs.bend as Defs
Lines 73-76 of lawful-bytes@0.1.1.0/defs.bend: https://jend.leeeet.dev/read.txt?path=lawful-bytes@0.1.1.0/defs.bend&start_line=73&end_line=76

import Base

# The first index j with from <= j < to where xs has c; to if there is none
# (for from <= to <= length(xs), as the laws assume).
def first(xs: List<&2, U32>, +from: Nat, +to: Nat, +c: U32) -> Nat:
  Nat.add(from, run_len(slice(xs, from, Nat.sub(to, from)), c))

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.sub
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/defs.bend&name=run_len
  https://jend.leeeet.dev/definition.txt?path=lawful-bytes@0.1.1.0/defs.bend&name=slice