ass='fl'>NA</span>)

<span class='fu'>isSingular</span>(<span class='no'>singularVar</span>)</div><div class='output co'>#&gt; The variable only takes one (non-missing) value: a. The variable contains 16.67 \% missing observations.</div><div class='input'><span class='fu'>isSingular</span>(<span class='no'>notSingularVar</span>)</div><div class='output co'>#&gt; No problems found.</div><div class='input'>
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    <h2>Contents</h2>
 