anchor.diff:        (visit seed-system-name))))
   
   (defmacro traverse-dependencies (seed-system-name (depender depended) &body body)
  +  "Explore the ASDF dependencies of a system.
  +
  +Starting with the system named `seed-system-name', this will traverse
  +the ASDF dependency graph.  Every time it finds a dependency, it will
  +bind `depender' to the name of the system that is doing the depending
  +and `depended' to the name of the system that is depended upon.  It
  +will then evaluate the provided body.
  +
  +If the body returns non-nil, this macro will delve into the
  +dependencies of `depended'.  If the body returns nil, this macro will
  +not explore `depended' and will instead continue to explore
  +`depender'."
     `(traverse-dependencies-fn ,seed-system-name
                                (lambda (,depender ,depended) ,@body)))
   
  
positive.code:     (string= word prefix :end1 (length prefix))))
  
  (defun shcl-package-name-p (package-name)
    (string-prefix-p "SHCL/" package-name))
  
  (defun shcl-system-name-p (system-name)
    (string-prefix-p "shcl/" system-name))
  
  (defun traverse-dependencies-fn (seed-system-name visit-fn)
  
negative.code:   (:export
     #:graph-dependencies #:graph-class-hierarchy #:undocumented-symbols
     #:undocumented-symbols-in-package #:verbose-echo-stream
     #:traverse-dependencies #:shcl-system-name-p
     #:shcl-package-name-p))
  (in-package :shcl/core/debug)
  
  