powerdomain progress
powerdomain progress

Ignore-this: 592f9c6046f05a27897b460edb2efe10
Show that powerdomains are endofunctors on PLT.  Further, they are monads with
the 'singleton' and 'join' operations.  Also make some progress on the additive
portion of the theory, dealing with emptyset and union.

darcs-hash:20140421064325-f399b-28967ee17de385c1124d82de1c5d27942f0870a7

robdockins/domains