Expression 22: left parenthesis, 0 , negative "N" Subscript, "r" "e" "f" , Baseline , right parenthesis0,−Nref
22
Expression 23: "f" Subscript, "r" "e" "f" , Baseline left parenthesis, "x" , right parenthesis equals StartFraction, "x" squared Over 4 "N" Subscript, "r" "e" "f" , Baseline , EndFraction minus "N" Subscript, "r" "e" "f" , Baselinefrefx=x24Nref−Nref
23
Expression 24: left parenthesis, "y" minus "f" Subscript, "r" "e" "f" , Baseline left parenthesis, "x" , right parenthesis , right parenthesis left parenthesis, "f" Subscript, "r" "e" "f" , Baseline left parenthesis, "P" Subscript, 0 , Baseline . "x" , right parenthesis minus "P" Subscript, 0 , Baseline . "y" , right parenthesis greater than 0y−frefxfrefP0.x−P0.y>0