Example:

require_once 'Currying.php';

$calc = new Currying(function ($operation, $operator1, $operator2){
    if( '+' == $operation ){
        return $operator1 + $operator2;
    }else if( '-' == $operation ){
        return $operator1 - $operator2;
    }else if( '*' == $operation ){
        return $operator1 * $operator2;
    }
});

$add = $calc('+');
$sub = $calc('-');
$multiply = $calc('*');

echo $add(20, 10); // 30
echo $sub(20, 10); // 10
echo $multiply(20, 10); // 200