Right. Got it now. I was thinking this morning about how one would implement constraints and realized that a constraint is implemented as a set of propagators. The propagators essentially propagate concrete aspects of one element to other elements as the constraint dictates.
Constraint propagation is really a forward-chaining system in which the propagators are the forward chaining rules. Right?
-- Russ
On 10/12/05, Christian Schulte <[EMAIL PROTECTED]> wrote:
Absolutely, it is the same as with a procedure implementing a function (in
the mathemical sense). A propagator just happens to be the implementation of
a constraint: constraint is declarative, propagator is (highly) operational.
Christian
--
Christian Schulte, http://www.imit.kth.se/~schulte/
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]] On Behalf Of David Hopwood
Sent: Wednesday, October 12, 2005 5:33 PM
To: Mozart Users
Subject: Re: Procedural vs. declarative
Russ Abbott wrote:
> Today's episode combines the procedural and declarative models that
> I've been working out to get constraint programming. I'm amazed at how
> well it seems to work out. What do you thing?
>
> http://cs.calstatela.edu/~wiki/index.php/Courses/CS_460/Fall_2005/Conc
>
urrent_logic_programming_in_Oz#Combining_the_two_approaches_to_get_constrain
t_programming
> -- Russ
# [...] The search rules are the distribution rules; the declarative code #
consists of the propagators. In this context the term ''propagator'' #
seems misleading. Propagators are really declarations (the assertions # or
constraints) that describe the required relationships among program #
variables and values.
I don't think the term "propagator" is misleading; it is an accurate name
for the construct that is used to *implement* a non-basic constraint. CTM
makes this distinction clear in the (relatively few) places where it uses
this term, e.g. on page 752.
--
David Hopwood < [EMAIL PROTECTED]>
____________________________________________________________________________
_____
mozart-users mailing list
[email protected]
http://www.mozart-oz.org/mailman/listinfo/mozart-users
_________________________________________________________________________________
mozart-users mailing list [email protected]
http://www.mozart-oz.org/mailman/listinfo/mozart-users
_________________________________________________________________________________ mozart-users mailing list [email protected] http://www.mozart-oz.org/mailman/listinfo/mozart-users
