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<head><title>regularSequenceCheck -- how much of a list is regular</title>
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<div><h1>regularSequenceCheck -- how much of a list is regular</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>regularSequenceCheck(X,A)</tt></div>
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<li><div class="single">Inputs:<ul><li><span><tt>X</tt>, a <a href="../../Macaulay2Doc/html/___List.html" title="the class of all lists -- {...}">List</a> or <a href="../../Macaulay2Doc/html/___Matrix.html" title="the class of all matrices">Matrix</a></span></li>
<li><span><tt>A</tt>, a <a href="../../Macaulay2Doc/html/___Ring.html" title="the class of all rings">Ring</a> or <a href="../../Macaulay2Doc/html/___Module.html" title="the class of all modules">Module</a></span></li>
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<li><div class="single">Outputs:<ul><li><span><span>an <a href="../../Macaulay2Doc/html/___Z__Z.html">integer</a></span></span></li>
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<div class="single"><h2>Description</h2>
<div>Given a list <tt>X</tt>, the function <tt>regularSequenceCheck</tt> gives an integer indicating how many initial elements of a <tt>List</tt> form a regular sequence.<table class="examples"><tr><td><pre>i1 : A = ZZ[x_1..x_4]/(x_4^2)
o1 = A
o1 : QuotientRing</pre>
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<tr><td><pre>i2 : regularSequenceCheck({x_1..x_4},A)
o2 = 3</pre>
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<p>This symbol is provided by the package <a href="index.html" title="computations involving regular sequences">Depth</a>.</p>
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<div class="single"><h2>Caveat</h2>
<div><tt>regularSequenceCheck</tt> merely checks the injectivity of the maps in question. It does not check to see if <tt>XA = A</tt>.</div>
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<div class="waystouse"><h2>Ways to use <tt>regularSequenceCheck</tt> :</h2>
<ul><li>regularSequenceCheck(List,Module)</li>
<li>regularSequenceCheck(List,Ring)</li>
<li>regularSequenceCheck(Matrix,Module)</li>
<li>regularSequenceCheck(Matrix,Ring)</li>
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