Natural.Gcd.greatest: 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 140-142 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=140&end_line=142

import Base
import bend-collections-laws-math@1.0.0.0/src/math/natural.bend as M

# every common divisor divides the gcd
def Gcd.greatest(+a: Nat, +b: Nat, +d: Nat, +ka: Nat, +kb: Nat, +ea: {a == Nat.mul(ka, d) : Nat}, +eb: {b == Nat.mul(kb, d) : Nat}) -> Type:
  dvd(d, M.gcd(a, b))

Uses (4):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.mul
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/spec/math/natural.bend&name=dvd
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/natural.bend&name=gcd