ƚ  1S  .   & & MathType-Hzy -y-&&  , zQ-Q-Symbol @؟ww wf-2 y2 "y2 y2 :y2 ":y2 :y2 -yTimes New Roman؟ww wf-2 7y2 7y2 b,y2 7y2 87y & "Systemf !\-