Hi, I am not sure I understand what you want correctly: in CLP, the `search' is the process of assigning values to all problem variables, resulting in a feasible solution, so the number of unassigned variables will always be zero if/when you have found a solution. Even for a MAX CSP problem, where you have `soft' constraints that can be violated, all the variables will still be assigned values. Am I missing something about your problem? Which constraint solver are you using? It seems a little odd to use $=/2 for your count_nonground predicate, firstly this implies that count_nonground/2 should be a constraint for your solver (which you would probably have to implement yourself), and secondly, in the common solver interface we use, $=/2 accepts variables with real intervals (i.e. they can take on real (non-integeral) values), while the number of nonground variables must be an integer. Cheers, Kish Stephen Flinter wrote: > Hi, > > I'm looking for a way to count the number of non-ground variables in a > list, such that I can use that value as a minimizing goal in the > bb_min or minimize predicate. > > i.e. something like: > > constraints(Xs, C) :- > (foreach(X, Xs) do > %% apply constraint on X > ), > > C $= count_nonground(Xs). > > .... > > solve(Xs) :- > constraints(Xs, C), > minimize(search(Xs), C). > > That is, I'm looking to implement a Max-CSP type search, where I'm > trying to minimize the number of unassigned variables. > > Any ideas? > > Thanks, > > Steve > > _______________________________________________ > ECLiPSe-Users mailing list > ECLiPSe-Users_at_...2... > http://www.crosscoreop.com/mailman/options/eclipse-users >Received on Wed Jan 09 2008 - 23:07:33 CET
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