def sub_mag

bend-collections-laws-crypto@1.0.0.0 · spec/math/f64.bend:184

import Base
import bend-collections-laws-crypto@1.0.0.0/src/math/f64.bend as F

184# (-1)^sa A + (-1)^sb B at a common scale x: equal magnitudes of opposite
185# signs cancel to +0 (round to nearest)
186def sub_mag(+sa: Bool, +a: Nat, +sb: Bool, +b: Nat, +x: Nat, c: Cmp) -> F.F64:
187  match c:
188    case GT{}:
189      round(sa, Nat.sub(a, b), x)
190    case LT{}:
191      round(sb, Nat.sub(b, a), x)
192    case EQ{}:
193      zero(False{})