ƚ  R ] .   &@ & MathTypeSymbol ؟ww w[f-2 ":y2 :y2 :y2 ,=y2 -y2 =y2 +yTimes New Roman؟ww w[f-2 ^6y2 (2y2 4y2 2y2 3yTimes New Roman؟ww w[f-2 yy2  xy2 yy2 xy & "System[f !-