n> <span class='kw'>&lt;-</span> <span class='fu'><a href='index_l.html'>index</a></span>(<span class='fl'>1</span>) <span class='kw'>%.%</span> <span class='fu'><a href='index_l.html'>index</a></span>(<span class='fl'>1</span>) <span class='kw'>%.%</span> <span class='no'>sqrt_l</span>

<span class='fu'>sqrt</span>(<span class='no'>iris</span><span class='kw'>[[</span><span class='fl'>1</span>]]<span class='kw'>[[</span><span class='fl'>1</span>]])</div><div class='output co'>#&gt; [1] 2.258318</div><div c