Natural.mid: def of bend-collections-laws-math@1.0.0.0
Import: import bend-collections-laws-math@1.0.0.0/src/math/natural.bend as Natural
Lines 171-176 of bend-collections-laws-math@1.0.0.0/src/math/natural.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/src/math/natural.bend&start_line=171&end_line=176

import Base

# Binary search for the last r in [lo, hi) where the test holds, given it
# holds at lo and fails at hi (reference section 8.5 notes the float-sqrt
# shortcut is wrong above 2^52; this search is exact). `more` is lo + 1 < hi
# and `ok` is the test at the midpoint; the fuel bounds the halvings.
def mid(+lo: Nat, +hi: Nat) -> Nat:
  Nat.div(Nat.add(lo, hi), 2n)

Uses (3):
  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.div