public static Object subtract(Object val0, Object val1) {
		val0 = guess(val0);
		val1 = guess(val1);
		if (val0 instanceof Color)
			return ((Color)val0).subtract(val1);
		if (val0 instanceof Size)
			return ((Size)val0).subtract(val1);
		if (val0 instanceof Number && val1 instanceof Number) {
			if (val0 instanceof Double || val1 instanceof Double)
				return ((Number)val0).doubleValue() - ((Number)val1).doubleValue();
			return ((Number)val0).intValue() - ((Number)val1).intValue();
		}
		return val0 == null ? null: val1 == null ? val0:
			Classes.toString(val0).replace(Classes.toString(val1), "");
	}