<?php
function callback1($m) {return c($m[1]);}
function callback2($n,$m) {
$o=$m[0];
$m[0]=' ';
return $o=='+' ? $n+$m : ($o=='-' ? $n-$m : ($o=='*' ? $n*$m : $n/$m));
}
function c($s){
}
$str = '(3 + 2) * 5';
echo c($str);
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