pan class='kw'>z</span> <span class='kw'>=</span> <span class='no'>zs</span>[<span class='no'>r</span>,,])
  })

  <span class='fu'><a href='https://rdrr.io/r/base/stopifnot.html'>stopifnot</a></span>(
    <span class='fu'><a href='https://rdrr.io/r/base/length.html'>length</a></span>(<span class='fu'><a href='https://rdrr.io/r/base/unique.html'>unique</a></span>(<span class='fu'><a href='https://rdrr.io/r/base/c.html'>c</a></span>(<span class='no'>l</span>, <span class='no'>ls</span>))) <span class='kw'>==