(PHP 4 >= 4.0.4, PHP 5, PHP 7)
Legendre symbol
int gmp_legendre ( GMP $a, GMP $p )
Compute the » Legendre symbol of a and p. p should be odd and must be positive.
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.
p