; selects the fifth 'para' child of the context node that has a type
; attribute with value warning
;
; Abbreviated XPath: para[@type='warning'][5]
; Full XPath: child::para[attribute::type='warning'][position()=5]

(define tree 
'(chapter
  (para "para1")
  (para (@ (type "warning")) "para 2")
  (para (@ (type "warning")) "para 3")
  (para (@ (type "warning")) "para 4")
  (para (@ (type "warning")) "para 5")
  (para (@ (type "warning")) "para 6"))
 )

; Low-level:
((node-reduce
    (select-kids (ntype?? 'para))
    (sxml:filter
     (node-join
      (select-kids (ntype?? '@))
      (select-kids (node-equal? '(type "warning")))))
    (node-pos 5))
 tree)

; SXPath:
((sxpath `( (((para (@ (equal? (type "warning"))))) 5 )  ))
 tree)

==>
((para (@ (type "warning")) "para 6"))