Return True for an input with units and a positive magnitude:

Return False for a dimension-less input with a positive magnitude:

Return False for a unit-ed input with a negative magnitude:

Percentages are considered unit-ed:

A directly-provided quantity will be assessed for its magnitude, even if it has a negative magnitude in another unit:

A quantity, when converted, will have its magnitude assessed after the conversion:

Quantities with zero magnitude return False: