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<h2 class="chapter">6 Expressions</h2>

<p><a name="index-expressions-243"></a><a name="index-addresses-244"></a><a name="index-numeric-values-245"></a>An <dfn>expression</dfn> specifies an address or numeric value. 
Whitespace may precede and/or follow an expression.

   <p>The result of an expression must be an absolute number, or else an offset into
a particular section.  If an expression is not absolute, and there is not
enough information when <samp><span class="command">as</span></samp> sees the expression to know its
section, a second pass over the source program might be necessary to interpret
the expression&mdash;but the second pass is currently not implemented. 
<samp><span class="command">as</span></samp> aborts with an error message in this situation.

<ul class="menu">
<li><a accesskey="1" href="Empty-Exprs.html#Empty-Exprs">Empty Exprs</a>:                  Empty Expressions
<li><a accesskey="2" href="Integer-Exprs.html#Integer-Exprs">Integer Exprs</a>:                Integer Expressions
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