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<head><title>target(ChainComplexMap) -- find the target of a map of chain complexes</title>
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<div><h1>target(ChainComplexMap) -- find the target of a map of chain complexes</h1>
<div class="single"><h2>Synopsis</h2>
<ul><li><div class="list"><dl class="element"><dt class="heading">Usage: </dt><dd class="value"><div><tt>target f</tt></div>
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<li><span>Function: <a href="_target.html" title="target of a map">target</a></span></li>
<li><div class="single">Inputs:<ul><li><span><tt>f</tt>, <span>a <a href="___Chain__Complex__Map.html">chain complex map</a></span></span></li>
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<li><div class="single">Outputs:<ul><li><span>the target chain complex of <tt>f</tt></span></li>
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<div class="single"><h2>Description</h2>
<div>In the example below, we have a map between two modules and extend it to a map between projective resolutions of the two modules. Then <tt>target</tt> gives the target of the map of chain complexes.<table class="examples"><tr><td><pre>i1 : R = ZZ[x,y,z];</pre>
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<tr><td><pre>i2 : M = R^1/(x,y,z);</pre>
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<tr><td><pre>i3 : N = R^1/(x^2,y^2,x*y*z,z^2);</pre>
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<tr><td><pre>i4 : g = map(N,M,x*y);
o4 : Matrix</pre>
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<tr><td><pre>i5 : f = res g;</pre>
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<tr><td><pre>i6 : target f
1 4 6 3
o6 = R <-- R <-- R <-- R <-- 0
0 1 2 3 4
o6 : ChainComplex</pre>
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(That was an expensive way of resolving <tt>N</tt>.)</div>
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