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63<a name="Expressions"></a>
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65<p>
66Next: <a href="Pseudo-Ops.html#Pseudo-Ops" accesskey="n" rel="next">Pseudo Ops</a>, Previous: <a href="Symbols.html#Symbols" accesskey="p" rel="previous">Symbols</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
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69<a name="Expressions-1"></a>
70<h2 class="chapter">6 Expressions</h2>
71
72<a name="index-expressions"></a>
73<a name="index-addresses"></a>
74<a name="index-numeric-values"></a>
75<p>An <em>expression</em> specifies an address or numeric value.
76Whitespace may precede and/or follow an expression.
77</p>
78<p>The result of an expression must be an absolute number, or else an offset into
79a particular section.  If an expression is not absolute, and there is not
80enough information when <code>as</code> sees the expression to know its
81section, a second pass over the source program might be necessary to interpret
82the expression&mdash;but the second pass is currently not implemented.
83<code>as</code> aborts with an error message in this situation.
84</p>
85<table class="menu" border="0" cellspacing="0">
86<tr><td align="left" valign="top">&bull; <a href="Empty-Exprs.html#Empty-Exprs" accesskey="1">Empty Exprs</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Empty Expressions
87</td></tr>
88<tr><td align="left" valign="top">&bull; <a href="Integer-Exprs.html#Integer-Exprs" accesskey="2">Integer Exprs</a>:</td><td>&nbsp;&nbsp;</td><td align="left" valign="top">Integer Expressions
89</td></tr>
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