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<div><h1>lookup -- look up methods</h1>
<div class="single"><h2>Description</h2>
<div><tt>lookup(M,A)</tt> -- provides the binary method named <tt>M</tt> for class <tt>A</tt>. The first place to look is <tt>A#M</tt>. The search proceeds with the parent of <tt>A</tt>, and so on.<p/>
<tt>lookup(M,A,B)</tt> -- provides the binary method named <tt>M</tt> for <tt>(A,B)</tt>. The first place to look is <tt>Y#(M,A,B)</tt> where <tt>Y</tt> is the younger of <tt>A</tt> and <tt>B</tt>. The search proceeds next with the parent of <tt>B</tt>, and so on. <p/>
<tt>lookup(M,A,B,C)</tt> -- provides the ternary method named <tt>M</tt> for <tt>(A,B,C)</tt>. The first place to look is <tt>Y#(M,A,B,C)</tt> where <tt>Y</tt> is the youngest of <tt>A</tt>, <tt>B</tt>, and <tt>C</tt>. The search proceeds with the parent of <tt>C</tt>, and so on.<p/>
<tt>lookup(M,A,B,C,D)</tt> -- provides the quaternary method named <tt>M</tt> for <tt>(A,B,C,D)</tt>. The first place to look is <tt>Y#(M,A,B,C,D)</tt> where <tt>Y</tt> is the youngest of <tt>A</tt>, <tt>B</tt>, <tt>C</tt>, and <tt>D</tt>. The search proceeds with the parent of <tt>D</tt>, and so on.<p/>
<tt>lookup x</tt> -- where <tt>x</tt> is a symbol or function, returns <tt>x</tt>.<p/>
If no method is found, then <a href="_null.html" title="the unique member of the empty class">null</a> is returned.<p/>
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<div class="single"><h2>See also</h2>
<ul><li><span><a href="__sh.html" title="length, or access to elements">#</a> -- length, or access to elements</span></li>
<li><span><a href="_install__Method.html" title="install methods">installMethod</a> -- install methods</span></li>
<li><span><a href="_youngest.html" title="the youngest member of a sequence">youngest</a> -- the youngest member of a sequence</span></li>
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