ƚ@@ R A .  @@& & MathType- ` B  8Symbol ww 0wQf2-2 hy2 hy2 hy2 y2 y2 y2 j-y2 y2 :-yTimes New Romanww 0wQf2-2 242 252 t652 t55 & "System2Qf2 !-