checkExpresion (OpApp op exp1 exp2) funDef state  | isLeft checkExp1 = checkExp1
                                   | isLeft checkExp2 = checkExp2
                                   | otherwise =  case op of
                                                        Index ->   if((fromRight2 checkExp1/= TArrInt)&&(fromRight2 checkExp2/=TInt))
                                                                   then Left(MismatchExtend TArrInt TInt (fromRight2 checkExp1) (fromRight2 checkExp2) (show (OpApp op exp1 exp2)))
                                                                   else checkExp2
                                                        Equal ->   if((fromRight2 checkExp1)/=(fromRight2 checkExp2))
                                                                   then Left(MismatchExtend TArrInt TInt (fromRight2 checkExp1) (fromRight2 checkExp2) (show (OpApp op exp1 exp2)))
                                                                   else checkExp2         
                                                        _ ->       if((fromRight2 checkExp1/= TInt)||(fromRight2 checkExp2/=TInt))
                                                                   then Left(MismatchExtend TInt TInt (fromRight2 checkExp1) (fromRight2 checkExp2) (show (OpApp op exp1 exp2)))
                                                                   else checkExp2          
                                  where
                                    checkExp1 = checkExpresion exp1 funDef state
                                    checkExp2 = checkExpresion exp2 funDef state