anchor.diff:  ;;;; ARGUMENTS
   
   (defun funinfo-arg? (fi var)
  -  (& (member var (funinfo-args fi) :test #'eq)
  +  (& (symbol? var)
  +     (member var (funinfo-args fi) :test #'eq)
        fi))
   
   (defun funinfo-arg-pos (fi x)
  
positive.code: ;;;; ARGUMENTS & VARIABLES
  
  (defun funinfo-var? (fi x)
    (& x (atom x)
       (? (funinfo-parent fi)
          (member x (funinfo-vars fi) :test #'eq)
          (!? (funinfo-vars-hash fi)
  
negative.code:   (!? (funinfo-parent fi)
        (& (not (funinfo-arg-or-var? fi x))
           (funinfo-toplevel-var? ! x))
        (funinfo-var? fi x)))
  
  (defun funinfo-global-variable? (fi x)
    (& (not (funinfo-var-or-lexical? fi x))
  