anchor.diff:  Note that in a slot definition, '() is infered to be a list while NIL is infered
   to be a boolean.
   
  -Non-basic form types are not infered (returns nil)."
  +Non-basic form types are not infered (returns nil).
  +Non-basic scalar types are derived to their own type (with `type-of')."
     (multiple-value-bind (found? value)
         (initform definition)
       (when found?
  
positive.code:                         general-type)))
                 (or (some #'derive-type '(string boolean list array hash-table integer
                                           complex number))
                     type))))))))
  
  (defun type-zero-initform-inference (definition)
  
negative.code:         ;; Default initform when type is missing:
          nil)))
  
  (defvar *initform-inference* 'type-zero-initform-inference
    "Fallback initform inference function.
  Set this to nil to disable inference.")
  (defvar *type-inference* 'basic-type-inference
    "Fallback type inference function.
  Set this to nil to disable inference.")
  
  (defun process-slot-initform (definition &key ; See `hu.dwim.defclass-star:process-slot-definition'.
                                             initform-inference
  