isset_variables  1266 Zend/zend_language_parser.y 		T_ISSET '(' isset_variables ')' { $$ = $3; }
isset_variables  1276 Zend/zend_language_parser.y isset_variables:
isset_variables  1278 Zend/zend_language_parser.y 	|	isset_variables ',' { zend_do_boolean_and_begin(&$1, &$2 TSRMLS_CC); } isset_variable { zend_do_boolean_and_end(&$$, &$1, &$4, &$2 TSRMLS_CC); }