anchor.diff:  (defparameter $ nil
     "Special form symbol for interpolation.")
   
  -(defparameter BR nil
  +(defparameter br nil
     "Special form symbol for printing paragraph seperators (double
     newline).")
  +
  +(defparameter \\ nil
  +  "Special form symbol for printing explicit newline tokens.")
   
   (defparameter [] nil
     "Special form symbol for wrapping expressions with brackets.")
  
positive.code: 	   :escape
  	   :$
  	   :br
  	   :[]
  	   :{}
  	   :tex
  
negative.code: (defun compile-break ()
    "Print double newline."
    `(format t "~%~%"))
  
  (defun compile-newline ()
    "Print explicit newline."
    `(format t "\\\\~%"))
  
  (defun compile-parenthesized (open close expressions)
    "Compile EXPRESSIONS parenthesized by OPEN and CLOSE."
  