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<head><title>Symbol _ Thing -- index variable</title>
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<div><h1>Symbol _ Thing -- index variable</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>s_v</tt></div>
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<li><span>Operator: <a href="__us.html" title="a binary operator, used for subscripting and access to elements">_</a></span></li>
<li><div class="single">Inputs:<ul><li><span><tt>s</tt>, <span>a <a href="___Symbol.html">symbol</a></span></span></li>
<li><span><tt>v</tt>, <span>a <a href="___Thing.html">thing</a></span></span></li>
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<li><div class="single">Outputs:<ul><li><span><span>an <a href="___Indexed__Variable.html">indexed variable</a></span></span></li>
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<div class="single"><h2>Description</h2>
<div>The subscript can be anything, even a mutable object. Often, the subscripts are numbers or sequences. Sequences usually print nicer than lists.<table class="examples"><tr><td><pre>i1 : x_(1,3)
o1 = x
1,3
o1 : IndexedVariable</pre>
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<tr><td><pre>i2 : x_{1,3}
o2 = x
{1, 3}
o2 : IndexedVariable</pre>
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Indexed variables can be used for ring variables.<table class="examples"><tr><td><pre>i3 : R = ZZ[x_(1,1)..x_(2,3),y_a..y_f]
o3 = R
o3 : PolynomialRing</pre>
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<tr><td><pre>i4 : gens R
o4 = {x , x , x , x , x , x , y , y , y , y , y , y }
1,1 1,2 1,3 2,1 2,2 2,3 a b c d e f
o4 : List</pre>
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