gmp_clrbit
    (PHP 4 >= 4.0.4, PHP 5)
gmp_clrbit -- Clear bit
Description
void 
gmp_clrbit ( resource &a, int index)
     Clears (sets to 0) bit index in
     a. The index starts at 0.
    
Note: 
      Unlike most of the other GMP functions, gmp_clrbit()
      must be called with a GMP resource that already exists (using
      gmp_init() for example). One will not be
      automatically created.
     
Example 1. gmp_clrbit() example 
<?php $a = gmp_init("0xff"); gmp_clrbit($a, 0); // index starts at 0, least significant bit echo gmp_strval($a) . "\n"; ?>
 |  
 
      The printout of the above program will be:
       | 
     See also gmp_setbit().