The function
dspec-undefiner
returns a form which would undefine dspec, whether or not
dspec
is currently defined.
CL-USER 66 > (dspec:dspec-undefiner '(defun foo))
(PROGN (FMAKUNBOUND (QUOTE FOO)) (SETF (DOCUMENTATION (QUOTE FOO) (QUOTE FUNCTION)) NIL))
LispWorks User Guide and Reference Manual - 21 Dec 2011