JCL.F;

Provides a range of arithmetic functions.

F;element{;element}...;?[P|r]

element	operators or operands (see below)
?P	moves the result (top stack entry) into the current parameter of the primary input buffer.
?r	moves the result (top stack entry) into the reference r. Can be a direct or indirect reference to a buffer.

+	Add last stack entry and penultimate stack entry. Store the result in stack entry 1.
-	Subtract last stack entry from penultimate stack entry. Store the result in stack entry 1.
*	Multiply the last two stack entries. Store the result in stack entry 1.
/	Divide stack entry 2 by stack entry 1. Store the result in stack entry 1.
R	Divide stack entry 2 by stack entry 1. Store the remainder in stack entry 1.
_	Reverse the last two stack entries.

r	A direct or indirect reference to a buffer or select register value to be put on the stack.
{C}literal	Literal value specified by literal.

The F; command uses a stack processor similar to, the one used by the F; function in jQL.

Commands are processed from left to right.

Each operand pushes a value on to the top of the push-down/pop-up stack.

The result of a calculation can be copied into any buffer with the question mark (?) operator.

Command	PIB Before	PIB After
`F;C100;%2;-;?%3`	`6^8^999^7^GHI`	`6^8^92^7^GHI`

Stack

100

%2 pushes a value of 8 (the 2nd parameter of the PIB) onto the stack.

Stack	`100`
	`8`

-subtracts last entry from penultimate entry, and replaces last entry 1 with the result of 92.

Stack

92

?%3 then copies the result to the 3rd parameter of the PIB, replacing the old value.