forVector number_ $ \xs -> xs == Vector.negate (Vector.negate xs)
forSliced number_ $ \xs -> VectorSlice.toVector xs == Vector.negate (VectorSlice.negate xs)
>>> negate (MkInterval 1 2 3) Just (MkInterval {months = -1, days = -2, microseconds = -3}) >>> negate (MkInterval (-2147483648) 0 0) Nothing