/span> concat : <span><a href="index.html#type-t">t</a> <a href="../../../Alg_structs/NonEmptyList/index.html#type-t">Alg_structs.NonEmptyList.t</a></span> <span>&#45;&gt;</span> <a href="index.html#type-t">t</a></code></dt><dd><p><code>concat xs</code> is the concatenation of all elements of <code>xs</code> into a single value using <code>op</code>.</p><p>This is equivalent to <code>List.fold_right op (NonEmptyList.tl xs)
      (NonEmptyList.hd xs)</code>.</p></dd></dl></details></div></div></div><dl><dt c