; selects all 'td' elements that have an attribute 'align'
;
; Abbreviated XPath: //td[@align]
; Full XPath: /descendant::td[attribute::align]

(define tree 
'(html
 (head (title "Slides"))
 (body
  (p
   (@ (align "center"))
   (table
    (@ (style "font-size: x-large"))
    (tr
     (td (@ (align "right")) "Talks ")
     (td (@ (align "center")) " = ")
     (td " slides + transition"))
    (tr (td) (td (@ (align "center")) " = ") (td " data + control"))
    (tr (td) (td (@ (align "center")) " = ") (td " programs"))))
  (ul
   (li (a (@ (href "slides/slide0001.gif")) "Introduction"))
   (li (a (@ (href "slides/slide0010.gif")) "Summary")))))
 )

; Low-level:
((node-reduce 
    (node-closure (ntype?? 'td))
    (sxml:filter
     (node-join
      (select-kids (ntype?? '@))
      (select-kids (ntype?? 'align)))))
 tree)

; SXPath:
((sxpath `(// (td (@ align))))
 tree)

; SXPath:
((sxpath `(// ((td) (@ align))))
 tree)

==>
((td (@ (align "right")) "Talks ")
 (td (@ (align "center")) " = ")
 (td (@ (align "center")) " = ")
 (td (@ (align "center")) " = "))