anchor.diff:  (defun square-bracket-fld-form-p (x)
     (and (fld-form-p x)
          (eq (fld-form-field x) '#.(fld-form-field '().[]))))
  +
   ;;;
   ;;; PARSE-NAMED-MONOMER-DESCRIPTION
   ;;;
  
positive.code:         (etypecase site
            (bond-site-info '_)
            (state-site-info (state-site-info-default site))))))
   
  (defun default-site-binding (monomer site-num &optional binding) 
    (funcall *default-site-binding* monomer site-num binding))
  
negative.code: (in-package #I@library/biochem)
  
  ;;;
  ;;; MONOMER concept - main role is to hold sites
  ;;;
  
  (define-macro defmonomer (name-lclass &body def)
    (mutils:let+ (((symbol lclass) (etypecase name-lclass
                                     (symbol (values name-lclass 'compartment))
  