Sign Evaluation and Comparison for mytype Numbers

Below x, y, z are of type mytype.

dd_boolean dd_Positive(x)

:
Returns dd_TRUE if x is considered positive, and dd_FALSE otherwise. In the GMPRATIONAL mode, the positivity recognition is exact. In the C double mode, this means the value is strictly larger than dd_zero.

dd_boolean dd_Negative(x) works similarly.

dd_boolean dd_Nonpositive(x)

:
Returns the negation of dd_Positive(x). dd_Nonnegative(x) works similarly.

dd_boolean dd_EqualToZero(x)

:
Returns dd_TRUE if x is considered zero, and dd_FALSE otherwise. In the GMPRATIONAL mode, the zero recognition is exact. In the C double mode, this means the value is inbetween dd_minuszero and dd_zero inclusive.

dd_boolean dd_Larger(x, y)

:
Returns dd_TRUE if x is strictly larger than y, and dd_FALSE otherwise. This is implemented as dd_Positive(z) where z is the subtraction of y from x. dd_Smaller(x, y) works similarly.

dd_boolean dd_Equal(x, y)

:
Returns dd_TRUE if x is considered equal to y, and dd_FALSE otherwise. This is implemented as dd_EqualToZero(z) where z is the subtraction of y from x.