anchor.diff:  (defpackage :tre
     (:use :tre-core)
     (:export :%backquote :backquote :quasiquote :quasiquote-splice
  +           :macroexpand
              :square :curly :accent-circonflex $))
   
   (in-package :tre-core)
  
positive.code: (defconstant +core-variables+
      '(*universe* *variables* *functions* *macros*
        *environment-path* *environment-filenames*
        *macroexpand-hook* *quasiquoteexpand-hook* *dotexpand-hook*
        *default-listprop* *keyword-package*
        *pointer-size*
        *assert* *targets*))
  
negative.code: (defmacro define-core-package ()
    `(defpackage :tre-core
       (:use :common-lisp :tre-init)
       (:shadow :read :peek-char :read-char)
       (:export ,@(all-exports)
                +builtins+)))
  
  