REMF
====

syntax: (remf <place> <indicator>)

This function removes the element <indicator> and the
value, which belongs to the indicator, from the list
<place>. It returns T, when the indicator was found,
otherwise NIL.

example:       >(setf pl '(a 1 b 2 c 3))
               (A 1 B 2 C 3)
               >(remf pl 'b)
               T