$re = '/^[\(\[]/';
$str = '[[VALUE],[VALUE]+1)
([VALUE],[VALUE]+1)
([123abc.VALUE],[VALUE]+[[VALUE.123])
[,-25]
[-25,]
[25, 25)
[-25, [VALUE]
[123abc.VALUE] ';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php