Description
resource 
gmp_gcd ( resource a, resource b )
     Calculate greatest common divisor of a and
     b. The result is always positive even if
     either of, or both, input operands are negative.
    
Example 1. gmp_gcd() example 
<?php $gcd = gmp_gcd("12", "21"); echo gmp_strval($gcd) . "\n"; ?>
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      The printout of the above program will be:
       |