(PHP 4 >= 4.0.4, PHP 5, PHP 7)
Negate number
GMP gmp_neg ( GMP $a )
Returns the negative value of a number.
Parameters:
a
Either a GMP number resource in PHP 5.5 and earlier, a GMP object in PHP 5.6 and later, or a numeric string provided that it is possible to convert the latter to a number.
Returns:
Returns -a, as a GMP number.