[Ur] simple example about constructing rects - guarded types?

[Marc Weber]

Excerpts from Marc Weber's message of Mon Dec 20 02:41:06 +0100 2010:
http://impredicative.com/wiki/index.php/Disjointness_fun_-_creating_records_using_type_level_functions

I've tried summarizing the examples on the wiki - because they
illustrate several features:
- type level function yielding a function creating an expression
- disjointness annotations

In which way is this related to the
e! guarded expression application?

Marc Weber