anchor.diff:      :seamless :selected :typemustmatch))
   
   (defun boolean? (attr)
  +  (declare (inline memq))
     (memq attr *boolean-attributes*))
   
   (define-global-parameter *core-attributes*
  
positive.code:     :ins :del :col :meter :output))
  
  (defun inline? (element)
    (memq element *inline-elements*))
  
  (define-global-parameter *paragraph-elements*
  
negative.code:     :dt :dd :figcaption :iframe :colgroup :td :th :output :summary :command))
  
  (defun paragraph? (element)
    (declare (inline memq))
    (memq element *paragraph-elements*))
  
  (define-global-parameter *end-tag-optional*
  