<?php
/**
 * used to model structured symbols.
 */
class Level
{
    var $a;
    var $b;
    var $aVol;
    var $bVol;
    
    function Level($a, $b, $aVol, $bVol)
    {
        $this->a    = $a;
        $this->b    = $b;
        $this->aVol = $aVol;
        $this->bVol = $bVol;
    }

    function getA()
    {
        return $this->a;
    }
    function getAVol()
    {
        return $this->aVol;
    }
    function getB()
    {
        return $this->b;
    }
    function getBVol()
    {
        return $this->bVol;
    }
}
?>