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<head><title>Symbol _ Ring -- get a ring variable by name</title>
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<div><h1>Symbol _ Ring -- get a ring variable by name</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>x_R</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>x</tt>, <span>a <a href="___Symbol.html">symbol</a></span>, or <span>a <a href="___Ring__Element.html">ring element</a></span></span></li>
<li><span><tt>R</tt>, <span>a <a href="___Ring.html">ring</a></span></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 variable of <tt>R</tt> whose name is <tt>x</tt></span></li>
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<div class="single"><h2>Description</h2>
<div><table class="examples"><tr><td><pre>i1 : R = ZZ[x,y,z];</pre>
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<tr><td><pre>i2 : use R;</pre>
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<tr><td><pre>i3 : S = ZZ[x,t];</pre>
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<tr><td><pre>i4 : x
o4 = x
o4 : S</pre>
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The symbol <tt>x</tt> now refers to the variable <tt>x</tt> in the ring <tt>S</tt>. There are various ways of now referring to <tt>x</tt> in the ring <tt>R</tt>.<table class="examples"><tr><td><pre>i5 : R_0
o5 = x
o5 : R</pre>
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<tr><td><pre>i6 : R_"x"
o6 = x
o6 : R</pre>
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<tr><td><pre>i7 : use R;</pre>
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<tr><td><pre>i8 : x
o8 = x
o8 : R</pre>
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<div class="single"><h2>See also</h2>
<ul><li><span><a href="___Ring_sp_us_sp__Z__Z.html" title="get a ring variable by index">Ring _ ZZ</a> -- get a ring variable by index</span></li>
<li><span><a href="___Ring_sp_us_sp__String.html" title="get a ring variable by name">Ring _ String</a> -- get a ring variable by name</span></li>
<li><span><a href="_use_lp__Ring_rp.html" title="install ring variables and ring operations">use(Ring)</a> -- install ring variables and ring operations</span></li>
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