def W64.sub
import bend-osdev-word64@0.1.1.0/word64.bend as Word64import Base
130def W64.sub(a: W64, b: W64) -> W64:
131 match a b:
132 case W64{ah, +al} W64{bh, +bl}:
133 W64{U32.sub(U32.sub(ah, bh), W64.bit(U32.is_lt(al, bl))), U32.sub(al, bl)}