anchor.diff:  (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."
  
positive.code: 	   :escape
  	   :$
  	   :br
  	   :[]
  	   :{}
  	   :tex
  
negative.code:     (list (case (car expression)
  	    ($         (apply #'compile-interpolation (cdr expression)))
  	    (br        (apply #'compile-break (cdr expression)))
              (\\        (apply #'compile-newline (cdr expression)))
  	    ({}        (compile-with-braces (cdr expression)))
  	    ([]        (compile-with-brackets (cdr expression)))
  	    (otherwise (apply #'compile-macro-call expression))))))
  