A GMP object, an int,
or a string that can be interpreted as a number following the same logic
as if the string was used in gmp_init with automatic
base detection (i.e. when base is equal to 0).
num2
The number subtracted from num1.
A GMP object, an int,
or a string that can be interpreted as a number following the same logic
as if the string was used in gmp_init with automatic
base detection (i.e. when base is equal to 0).