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<head><title>someTerms -- select some terms of a polynomial</title>
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<div><h1>someTerms -- select some terms of a polynomial</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>someTerms(f,i,n)</tt></div>
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<li><div class="single">Inputs:<ul><li><span><tt>f</tt>, <span>a <a href="___Ring__Element.html">ring element</a></span>, in a polynomial ring</span></li>
<li><span><tt>i</tt>, <span>an <a href="___Z__Z.html">integer</a></span>, the starting index</span></li>
<li><span><tt>n</tt>, <span>an <a href="___Z__Z.html">integer</a></span>, the number of terms to select</span></li>
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<li><div class="single">Outputs:<ul><li><span><span>a <a href="___Ring__Element.html">ring element</a></span>, the <tt>n</tt> terms of the polynomial <tt>f</tt> starting with the <tt>i</tt>-th one</span></li>
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<div class="single"><h2>Description</h2>
<div>The index i is 0-based, and a negative number refers to location from the end of the polynomial.<table class="examples"><tr><td><pre>i1 : R = ZZ[a..d];</pre>
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<tr><td><pre>i2 : f = (a+2*b-3)^2
2 2
o2 = a + 4a*b + 4b - 6a - 12b + 9
o2 : R</pre>
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<tr><td><pre>i3 : someTerms(f,0,1) -- the lead term
2
o3 = a
o3 : R</pre>
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<tr><td><pre>i4 : someTerms(f,-1,1) -- the last term
o4 = 9
o4 : R</pre>
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<tr><td><pre>i5 : someTerms(f,-2,2) -- the last 2 terms
o5 = - 12b + 9
o5 : R</pre>
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Here is an example whre the coefficient ring is also a polynomial ring.<table class="examples"><tr><td><pre>i6 : S = R[x,y,z];</pre>
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<tr><td><pre>i7 : f = (x*(a-b)+y^2+a-1)^2
4 2 2 2 2 2 2
o7 = y + (2a - 2b)x*y + (a - 2a*b + b )x + (2a - 2)y + (2a - 2a*b - 2a
------------------------------------------------------------------------
2
+ 2b)x + a - 2a + 1
o7 : S</pre>
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<tr><td><pre>i8 : someTerms(f,-1,1) -- the last term
2
o8 = a - 2a + 1
o8 : S</pre>
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<tr><td><pre>i9 : someTerms(f,-2,2) -- the last 2 terms
2 2
o9 = (2a - 2a*b - 2a + 2b)x + a - 2a + 1
o9 : S</pre>
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<div class="single"><h2>See also</h2>
<ul><li><span><a href="_monomials.html" title="matrix of monomials in a ring element or matrix">monomials</a> -- matrix of monomials in a ring element or matrix</span></li>
<li><span><a href="_coefficients.html" title="monomials and their coefficients">coefficients</a> -- monomials and their coefficients</span></li>
<li><span><a href="_terms.html" title="provide a list of terms of a polynomial">terms</a> -- provide a list of terms of a polynomial</span></li>
<li><span><a href="_lead__Term.html" title="get the greatest term">leadTerm</a> -- get the greatest term</span></li>
</ul>
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<div class="waystouse"><h2>Ways to use <tt>someTerms</tt> :</h2>
<ul><li>someTerms(RingElement,ZZ,ZZ)</li>
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