+<sect3 id="decl-type-sigs">
+<title>Declaration type signatures</title>
+<para>A declaration type signature that has <emphasis>explicit</emphasis>
+quantification (using <literal>forall</literal>) brings into scope the
+explicitly-quantified
+type variables, in the definition of the named function(s). For example:
+<programlisting>
+ f :: forall a. [a] -> [a]
+ f (x:xs) = xs ++ [ x :: a ]
+</programlisting>
+The "<literal>forall a</literal>" brings "<literal>a</literal>" into scope in
+the definition of "<literal>f</literal>".
+</para>
+<para>This only happens if the quantification in <literal>f</literal>'s type
+signature is explicit. For example:
+<programlisting>
+ g :: [a] -> [a]
+ g (x:xs) = xs ++ [ x :: a ]
+</programlisting>
+This program will be rejected, because "<literal>a</literal>" does not scope
+over the definition of "<literal>f</literal>", so "<literal>x::a</literal>"
+means "<literal>x::forall a. a</literal>" by Haskell's usual implicit
+quantification rules.
+</para>
+</sect3>
+
+<sect3 id="pattern-type-sigs">