def dw

bend-collections-laws-math@1.0.0.0 · proofs/math/natural/gcd.bend:88

import Base

88# the quotient g / d, for d | a (a == ka d) and d | b (b == kb d)
89def dw(fuel: Nat, +a: Nat, +b: Nat, +ka: Nat, +kb: Nat) -> Nat:
90  match fuel b:
91    case 0n _:
92      ka
93    case 1n+f 0n:
94      ka
95    case 1n+f 1n+ +bp:
96      dw(f, 1n+bp, Nat.mod(a, 1n+bp), kb, Nat.sub(ka, Nat.mul(Nat.div(a, 1n+bp), kb)))