er popup-to-left"><span class="copy-popup-icon"></span><span>Content copied to clipboard</span></div></span></div></div><p class="paragraph">Creates a <a href="-not-empty-set/index.html">NotEmptySet</a> starting with a <a href="-not-empty-set.html">head</a> and containing all the elements of the optional <a href="-not-empty-set.html">tail</a>.</p></div></div>
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