SETF


syntax: (setf {<place> <value> ...})

This function stores the value into the place. SETF
specially has the function to change the value of a
variable. Further it can change a certain element of
a list or can change a certain character of a list or
string. If more than one place-value pair is defined,
then the pairs will be worked out sequentially. In
Babylon Lisp only one place-value pair is permitted.

example:       >(setf numbers '(1 2 3 4 5))
               (1 2 3 4 5)
               >numbers
               (1 2 3 4 5)