href="../module-type-S/index.html#type-t">t</a> = int</code></dt><dd><p><code>op</code> is <code>(+)</code> and <code>unit</code> is 0</p></dd></dl><dl><dt class="spec module" id="module-Product"><a href="#module-Product" class="anchor"></a><code><span class="keyword">module</span> <a href="Product/index.html">Product</a> : <a href="../index.html#module-type-S">S</a> <span class="keyword">with</span> <span class="keyword">type</span> <a href="../module-type-S/index.html#type-t">t</a> = int</code></dt><dd><p