fxnilgnilxfxgyzgfxyz++xnilx++xgyzg++xyznullniltruenullgxyfalsememnilyfalsememgxyzor=yzmemxzmemxmaxxnotnullxmaxggnilxymax'xymaxgggxyzumax'maxggxyzuf2nil0g2++2null1true0false0mem2or2=2max1not1max'2u0FULL./TRS/SK90/4.28.trs