$ ../c/retrieve ixin.ixin dump-node 4
((@)
 (section
   (@)
   (title (@) "Terminology")
   (para (@)
         "This section first introduces the fundamental data structure around which IXIN revolves conceptually, and then defines terms used in the specification to describe the file format's concrete representations.")
   (menu (@)
         (menuentry
           (@)
           (ix-menunode (@ (ix-coord "(node 5)")))
           (menutitle (@) "associative array")
           (menucomment (@) "In mind, in memory."))
         (menuentry
           (@)
           (ix-menunode (@ (ix-coord "(node 6)")))
           (menutitle (@) "representations")
           (menucomment (@) "On view, on disk.")))))a

$ ../c/retrieve ixin.ixin dump-node 5
((@)
 (subsection
   (@)
   (title (@) "associative array")
   (para (@)
         (strong (@) "NB")
         ": Unlike the other definitions (see "
         (xref (@) (xrefnodename (@) "representations"))
         " which describe concrete representations, those in this subsection describe a conceptual data structure and its related algorithms.")
   (table (@)
          (tableitem
            (@)
            (tableterm (@) "associative array")
            (ix-indexterm (@ (ix-coord "(dts cp 4)")))
            (item (@)
                  (para (@)
                        (ix-indexterm (@ (ix-coord "(dts cp 2)")))
                        " A (possibly ordered) set of pairs of objects. The first in the pair is the "
                        (dfn (@) "key")
                        ", and the second the "
                        (dfn (@) "value")
                        ".")
                  (ix-float
                    (@ (ix-coord "(floset Figure 0)"))
                    (verbatim
                      (@ (xml:space "preserve"))
                      "KEY => VALUE")
                    (caption
                      (@)
                      "The association between a "
                      (var (@) "key")
                      " and a "
                      (var (@) "value")
                      "."))
                  (para (@)
                        "A key may appear only once in an array; it is unique.  A value may appear any number of times.  For example:")
                  (ix-float
                    (@ (ix-coord "(floset Figure 1)"))
                    (verbatim
                      (@ (xml:space "preserve"))
                      "A => 5
B => 4
C => 4
D => 2")
                    (caption
                      (@)
                      "An example associative array, with four associations,showing unique keys ("
                      (code (@) "A")
                      ", "
                      (code (@) "B")
                      ", "
                      (code (@) "C")
                      ", "
                      (code (@) "D")
                      ")and non-unique values ("
                      (code (@) "5")
                      ", "
                      (code (@) "4")
                      ", "
                      (code (@) "2")
                      ")."))
                  (para (@)
                        (ix-indexterm (@ (ix-coord "(dts cp 1)")))
                        (ix-indexterm (@ (ix-coord "(dts cp 9)")))
                        (ix-indexterm (@ (ix-coord "(dts cp 22)")))
                        (ix-indexterm (@ (ix-coord "(dts cp 14)")))
                        " Other names for associative array are: alist, dictionary, ordered-map, hash table.")))
          (tableitem
            (@)
            (tableterm (@) "look up")
            (ix-indexterm (@ (ix-coord "(dts cp 20)")))
            (item (@)
                  (para (@)
                        (ix-indexterm (@ (ix-coord "(dts cp 6)")))
                        "You "
                        (dfn (@) "look up")
                        " information from an associative array, specifying the key and obtaining as a result the associated value, or the boolean value "
                        (code (@) "false")
                        " if there is no such key.  ("
                        (strong (@) "NB")
                        ": The file format never makes use of boolean values, so there is no risk of confusion.)"))))))