66"></a> <a name="%_idx_68"></a></p>
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<h2><a href="r5rs-Z-H-2.html#%_toc_%_sec_3.3">3.3&nbsp;&nbsp;External representations</a></h2>
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An important concept in Scheme (and Lisp) is that of the <em>external
representation</em> of an object as a sequence of characters.  For example,
an external representation of the integer 28 is the sequence of
characters ``<tt>28</tt>'', and an external representation of a list consisting
of the integers 8 and 13 is the sequence of 