Got it right this time

Curried roles are simply roles that have been provided with a
parameter, but before they have been fully instantiated by punning or
being mixed in a class. [Synopse](https://design.perl6.org/S14.html),
for once, was useful.

Refs #1306

doc/Type/Metamodel/CurriedRoleHOW.pod6

@@ -29,12 +29,36 @@ instantiation of it. This meta-object represents those "partial types"
 as both a way to curry on your way to a full specialization, but also
 as a way to do type-checking or punning.
 
-You can use C<new_type> as in most of the Metamodel namespace, to create new
-types:
+This class will show up in parametrized roles. For instance:
 
-    my $a = Metamodel::CurriedRoleHOW.new_type("zipi");
+=begin code
+role Zipi[::T] {
+    method zape { "Uses " ~ T.^name };
+}
+role Zipi[::T, ::Y] {
+    method zape { "Uses " ~ T.^name ~ " and " ~ Y.^name };
+}
+for Zipi[Int], Zipi[Int,Str] -> $role {
+    say $role.HOW;
+    say $role.new().zape;
+}
+# OUTPUT:
+# Perl6::Metamodel::CurriedRoleHOW.new
+# Uses Int
+# Perl6::Metamodel::CurriedRoleHOW.new
+# Uses Int and Str
+=end code
 
-I<Note>: As most of the Metamodel classes, this class is here mainly for
-illustration purposes and it's not intended for the final user.
+Since there are several variants of C<Zipi>, providing a parameter I<curries>
+it, but it's still up to the compiler to find out the actual realization taking
+into account the C<ParametricRoleGroup>, so these (partially instantiated) roles
+show up as C<Metamodel::CurriedRoleHOW> as shown in the example; even if there's
+a single parameter an instantiated role will also be of the same type:
+
+    role Zape[::T] {};
+    say Zape[Int].HOW; #: «Perl6::Metamodel::CurriedRoleHOW.new␤»
+
+I<Note>: As most of the C<Metamodel> classes, this class is here mainly for
+illustration purposes and it's not intended for the final user to instantiate.
 
 =end pod