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<div><a href="index.html" title="">Macaulay2Doc</a> > <a href="_ideals.html" title="">ideals</a> > <a href="_intersection_spof_spideals.html" title="">intersection of ideals</a></div>
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<div><h1>intersection of ideals</h1>
<div>Use <a href="_intersect.html" title="compute an intersection">intersect</a> to compute the intersection of two or more ideals.<table class="examples"><tr><td><pre>i1 : R = QQ[a..d];</pre>
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<tr><td><pre>i2 : intersect(ideal(a,b),ideal(c*d,a*b),ideal(b*d,a*c))
o2 = ideal (b*c*d, a*c*d, a*b*d, a*b*c)
o2 : Ideal of R</pre>
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The command <a href="_intersect.html" title="compute an intersection">intersect</a> will only work with proper ideals. To intersect an ideal with a ring, use <a href="_select__In__Subring.html" title="select columns in a subring">selectInSubring</a> along with the elimination ordering, see <a href="___Eliminate.html" title="elimination order">Eliminate</a>.</div>
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