* SWAP(.V1, .V2) - Exchange the contents of two variables.
*  The variables must be prefixed with the name operator
*  when the function is called.

        DEFINE('SWAP(X,Y)TEMP')              :(SWAP_END)
SWAP    TEMP = $X
        $X = $Y
        $Y = TEMP                            :(RETURN)
SWAP_END