[gecode-users] finding number of propagators for s Space, relation to floundering

[Christian Schulte]

There is no guarantee that propagators detect entailment perfectly! So, no
bug.

A space has a function propagators() that returns the number of propagators
in a space.

Cheers
Christian

--
Christian Schulte, www.gecode.org/~schulte
Professor of Computer Science, KTH, cschulte at kth.se
Expert Researcher, SICS, cschulte at sics.se


-----Original Message-----
From: users-bounces at gecode.org [mailto:users-bounces at gecode.org] On Behalf
Of Kish Shen
Sent: Tuesday, June 30, 2015 5:15 AM
To: users at gecode.org
Subject: Re: [gecode-users] finding number of propagators for s Space,
relation to floundering

On 29/06/2015 23:51, Kish Shen wrote:
>
> ?- A :: 1 .. 20, gfd : min([100, A], M), get_constraints_number(M, D).
>
> This shows that the variable M (and I also checked A, not shown here) 
> still have a propagator attached to it

Thinking about this, I think the propagator might be a constraint linking M
and A, as Gecode cannot unify the variables as ic does....

However, I was actually looking at argmin when I noticed that there was a
propagator attached when the constraint was satisfied, but I decided to look
at min instead as ic does not have argmin.

I can't show the ECLiPSe execution with argmin, as that is on a VNC window
that I can't use cut and paste on, but here is what I tried:

min_index([1,2,3,1,4], I), get_constraints_number(I, D).

I = I{[1,4]}
D = 1

so there is 1 propagator attached to I in this case, when min_index
(argmin) is entailed.

Cheers,

Kish


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