Здравствуйте! В clocc/src/port/sys имеется функция
(defun variable-special-p (symbol)
"Return T if the symbol names a global special variable."
#+(and allegro (not (version>= 6))) (clos::variable-special-p symbol nil)
#+(and allegro (version>= 6)) (excl::variable-special-p symbol nil)
#+clisp (sys::special-variable-p symbol)
#+cmu (walker:variable-globally-special-p symbol)
#+gcl (si:specialp symbol)
#+lispworks (eq :special (hcl:variable-information symbol))
#+lucid (system:proclaimed-special-p symbol)
#+sbcl (sb-walker:var-globally-special-p symbol)
#-(or allegro clisp cmu gcl lispworks lucid sbcl)
(error 'not-implemented :proc (list 'variable-special-p symbol)))