anchor.diff:  ;;;;     (when rt-arg 
   ;;;;       (unless (sum-expression-p rt-arg)
   ;;;;         (b-error "Invalid argument to reaction-type: ~S.  Expecting a {na A + nb B + nb C....}" rt-arg))
  -;;;;       rt-arg.(map-terms #'check-term))))+;;;;       rt-arg.(map-terms #'check-term))))
  
positive.code: ;;; File: reaction-type.lisp
  ;;; Description:  
  
  ;;; $Id: reaction-type.lisp,v 1.7 2008/01/17 00:11:58 amallavarapu Exp $
  
  (in-package #I@library/biochem)
  
  
negative.code:     (cond
       ((> (length loc-classes) 1)
        (b-error "Unable to determine location class for {~{~S~^ + ~} ~A ~{~S~^ + ~}} ~
                  ~&-- have you forgotten to assign sublocations (e.g., {X @ :inner})?"
                 clhs op crhs))
       ((null loc-classes)
        (b-error "Unable to determine location class for {~{~S~^ + ~} ~A ~{~S~^ + ~}}."
                 clhs op crhs))
  