ƚ H & .  & & MathType0Times New Roman؟ww w f- 2 `EDCe 2 ` BACe2 `  A 2 `` ande2 `  n 2 `DECe 2 `ZABCeSymbol ؟ww w f-2 `B2 `h=B2 ` B2 `B2 `=B2 `4B & "System f !-