 Is this mixed amount non-zero, ignoring its display precision?
--
-- A convenient alias for not . mixedAmountIsZero.
maIsNonZero :: MixedAmount -> Bool
maIsNonZero = not . mixedAmountIsZero

--
maIsNonZero :: MixedAmount -> Bool
maIsNonZero = not . mixedAmountIsZero
maIsNonZero = not . mixedAmountIsZero