From ricciott at cs.unibo.it  Tue Oct  2 04:51:18 2007
From: ricciott at cs.unibo.it (Wilmer Ricciotti)
Date: Tue, 2 Oct 2007 10:51:18 +0200
Subject: [POPLmark] Solution written in Matita updated
Message-ID: <20071002085118.GA304@cs.unibo.it>

Dear All,

here is an update to my solution written in Matita. This update is
actually a substantial rewrite, in which we tried to make the proofs as
compact as possible. 

The new version is 558 LOCs as opposed to the 1460 LOCs in the original 
version: the reduction was achieved by avoiding the use of swaps and by
replacing complete induction over types (used in the proof of
transitivity) with an induction on the well-formedness of the type (this
is possible thanks to the use of smarter statements for narrowing and 
transitivity).

The proofs also underwent a general clean-up.

Both the new and the old solution can be found at the following URI:
http://ricciott.web.cs.unibo.it/

Regards.
-- 
Wilmer Ricciotti