m</li><li class="src short"><span class="keyword">type</span> <a href="#t:Writer">Writer</a> w = <a href="../mtl-2.2.2/Control-Monad-Writer-Lazy.html#t:WriterT" title="Control.Monad.Writer.Lazy">WriterT</a> w <a href="../base-4.12.0.0/System-IO.html#t:IO" title="System.IO">IO</a> ()</li><li class="src short"><span class="keyword">class</span> (<a href="../base-4.12.0.0/Data-Monoid.html#t:Monoid" title="Data.Monoid">Monoid</a> w, <a href="../base-4.12.0.0/Data-Monoid.html#t:Monoid" title="Data.Monoid">Monoid