stead has a type <code>'a t</code> where the <i>'a</i> can be anything (ie: <code>'a list</code>, <code>'a option</code>).</p><p>It satisfies the monoid laws at the functor level:</p><ul><li><p>The <a href="Bastet/List/Plus/index.html"><code>Bastet.List.Plus</code></a></p><p><code>List.append</code> with <code>[]</code> as the empty element <code>(List.append, [])</code>:</p><pre><code class="ml"># let empty: int list = [];;
val empty : int list = []

# let satisfies_identity_law = List.append [1; 2; 3] emp