[PPL-devel] [Fwd: some questions about PPL]

[Roberto Bagnara]

-------- Original Message --------
Subject: some questions about PPL
Date: Tue, 7 Jun 2005 00:58:20 -0400
From: Jie Ouyang <ouyang.jie at gmail.com>
Reply-To: Jie Ouyang <ouyang.jie at gmail.com>
To: bagnara at cs.unipr.it

Hello Dr. Bagnara,

I started a thread on the news group comp.lang.prolog about anonymous
variables in prolog language. Thank you very much for your reply. Here
I have some newbie questions about PPL since I just started to use it
to do some logic program analysis. Say a predicate, P(A,B,C), appears
in the body of another predicate, e.g. P1(...):- ...,P(D,E,F). It is
easy to see that the variables of P are renamed and they correspond to
different space dimensions. If we have the constaints of P defined on
A,B,C, is there an easy way to map the constaints to the space
dimensions D,E,F? The way I handle this now is to first use
ppl_Polyhedron_map_space_dimensions to do the mapping: A-D,B-E,C-F.
Then get the constraints which are defined on A,B,C,D,E,F. Since I
don't want the effect of A,B,C after the mapping, I have to remove all
constaints defined on A,B,C only and get the constraints system
defined on D,E,F eventually. This procedure seems tedious and easily
to miss something. So I'd like to find a better way to do it.

I hope this question does not disturb you and look forward to your
reply. I am sorry if I missed some thing in the manual about this
issue.

cheers,

Jie Ouyang


-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it