anchor.diff:  (in-package #:ltp/common/mop/singleton)
   
   
  +;; -- Singleton Class Definition
   
   (defclass singleton (standard-class)
     ())
  
positive.code: (validate-class singleton)
  
  
  (defclass singleton-slot-definition (standard-slot-definition)
    ;; TBD: SLOT-DEFINITION (??)
    ()
    (:default-initargs
     :allocation :class))
  
negative.code: 
  ;; MOP Interop ...
  
  ;; --
  
  ;; Applications TD
  ;; - Use for internal representation of "Application Personalities" in
  ;;   the Lisp Environment - Class definitions, method definitions, and
  ;;   runtime application protocols.
  ;;
  ;; - Use for internal representation of bytecode ABIs (host ABIs,
  ;;   and toolchain ABIs)
  ;;
  ;; - Extend SINGLETON => SINGLETON-FUNCALLABLE-INSTANCE
  ;;
  ;;   - Use in definitions of external API forms - onto external type
  ;;     schema, as also extending SINGLETON)
  ;;
  ;;   - Observe XMI as a serialized representation of MOF (subsq. UML and
  ;;     other metamodels tractably extending OMG MOF) towards
  ;;     consideration with regards to portable definitions for such type
  ;;     schema. (NB: MOF and RDF may occupy different domains, per se.
  ;;     Note, however, the perhaps visually-oriented syntax of the RDF
  ;;     metamodel defined in OMG ODM)
  ;;
  ;;   - Note that this is not, per se, for redefining any single manner
  ;;     of knowledge representation system
  
  ;; TBD: SINGLETON-FUNCALLABLE-INSTANCE & CLASS-OWNED-METHOD definitions
  ;;
  ;; - NB: Common Lisp GENERIC-FUNCTION metaobjects as globally scoped
  ;;       objects, principally extending on a semantics of the Lisp
  ;;       function as a first order object, for purposes of definining
  ;;       polymorphic functions in Common Lisp programs
  ;;
  ;; - NB: Polymorphic functions in Simula and subsq.
  ;;
  ;; - NB: Type signatures in SML
  
  
  ;; TBD: SINGLETON usage in _static dispatching_ w/ portable extensions
  ;; onto CLtL2+MOP standard generic functions and standard methods - at
  ;; least insofar as may be portably integrated with any number of PCL
  ;; implementations.
  
  #+nil
  (eval-when ()
  