<a href="#Type_definitions">defined types</a>, and
<a href="#Type_parameter_declarations">type parameters</a> are called <i>named types</i>.
An <a href="#Alias_declarations">alias</a> denotes a named type if the type given in the alias declaration is a named type.
All named types are <a href="#Type_identity">distinct</a>.
</p>

<h3 id="Boolean_types">Boolean types</h3>

<p>