Re: [eclipse-users] ``tentative'' constraints?

From: Joachim Schimpf (Independent Contractor) <jschimpf_at_...5...>
Date: Tue, 20 Nov 2007 16:52:42 +1100
Ulrich Scholz wrote:
> Dear all,
> 
> the repair library introduces tentative assignments to variables.  
> 
> Is there a way to have ``tentative'' constraints.  In other words, is it
> possible to post a constraint, then post some others, and finally to revoke
> the first without revoking the others? 


In lib(repair) or lib(tentative), constraints are only _monitored_
for violation.  So, instead of explicitly revoking constraints,
you can just ignore the fact that they are violated (the only
disadvantage being that they continue to consume memory and runtime,
but on the positive side, they can be reactivated).

In lib(tentative), constraints can be given a weight.  However,
this is currently an integer. If we would change that to allow
an integer tentative variable, then we could modify the weight
during the search (in particular set it to zero), which would be
useful for quite a number of local search techniques.  The
library(tentative) is relatively new but somewhat incomplete -
if anyone would take an interest and build in these extensions,
that would be a valuable contribution!


-- Joachim
Received on Tue Nov 20 2007 - 05:53:52 CET

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