ƚ ` PS g .  ` & & MathType- @  ^  Times New Roman؟ww w2f-2 1y2 [2y2 41y2 [2yTimes New Roman؟ww w2f-2 |xy2 xy2 yy2 yy 2 orune 2 ZriseSymbol ߠ؟ww w2f-2 J-i2 J-i2  =i & "System2f !-