123 + addition Group 4 - subtraction Group 5 = equal to not equal to less than > greater than less than or equal to >= greater than or equal to OR logical and bitwise OR Group 7 EOR logical and bitwise Exclusive OR Group 6 AND logical and bitwise AND All operators in each group have equal priority and will be dealt with on a left to right basis – in other words in order in each line. Some of the operators should be familiar by now, others may need explanation. NOT is most often used to reverse the result of a test, eg Group 1 IF NOT (X=5) THEN.... Clearly this example could be written IF X 5 THEN but the operator NOT is often needed when using functions, eg IF NOT FNVALID THEN...
Functions include all the predefined functions such as SQR , SIN , ASC etc and user defined functions like FNVALID . Parentheses can be used to ensure that everything within the parentheses is evaluated before any other calculations take place. Indirection operators are described in chapter 39. Raise to the power, eg Group 2 3^2=9 3^3=27 Group 3 and Group 4 These contain all the usual arithmetic operators. Nothing unexpected here.