def sub
import bend-collections-laws-math@1.0.0.0/src/math/w64.bend as W64import Base
import bend-collections-laws-math@1.0.0.0/src/math/u64.bend as W
70# a - b mod 2^64
71def sub(+a: W.U64, +b: W.U64) -> W.U64:
72 W.U64{U32.sub(lo(a), lo(b)), U32.sub(U32.sub(hi(a), hi(b)), b32(U32.is_lt(lo(a), lo(b))))}