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<head><title>OO _ Variety -- the structure sheaf</title>
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<div><h1>OO _ Variety -- the structure sheaf</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>OO_X</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="___Variety.html">variety</a></span>, a variety</span></li>
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<li><div class="single">Outputs:<ul><li><span>the structure sheaf of <tt>X</tt>.</span></li>
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<div class="single"><h2>Description</h2>
<div><table class="examples"><tr><td><pre>i1 : R = QQ[x,y,z]/(y^2*z-x*(x-z)*(x-37*z));</pre>
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<tr><td><pre>i2 : X = Proj R
o2 = X
o2 : ProjectiveVariety</pre>
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<tr><td><pre>i3 : OO_X
o3 = OO
X
o3 : SheafOfRings</pre>
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<tr><td><pre>i4 : HH^1(OO_X)
1
o4 = QQ
o4 : QQ-module, free</pre>
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<tr><td><pre>i5 : HH^0(OO_X(3))
9
o5 = QQ
o5 : QQ-module, free</pre>
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<div class="single"><h2>See also</h2>
<ul><li><span><a href="___Coherent__Sheaf.html" title="the class of all coherent sheaves">CoherentSheaf</a> -- the class of all coherent sheaves</span></li>
<li><span><a href="_cohomology.html" title="general cohomology functor">cohomology</a> -- general cohomology functor</span></li>
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