a__p00a__psXmarkXa__leq0Ytruea__leqsX0falsea__leqsXsYa__leqmarkXmarkYa__iftrueXYmarkXa__iffalseXYmarkYa__diffXYa__ifa__leqmarkXmarkY0sdiffpXYmarkpXa__pmarkXmarkleqX1X2a__leqmarkX1markX2markifX1X2X3a__ifmarkX1X2X3markdiffX1X2a__diffmarkX1markX2mark00marksXsmarkXmarktruetruemarkfalsefalsea__pXpXa__leqX1X2leqX1X2a__ifX1X2X3ifX1X2X3a__diffX1X2diffX1X2