Dear Joshua, On 20.04.2007, at 19:35, Joshua ben Jore wrote:
I observed that the domain was getting partially solved already.
Constraint propagation reduces the variable domains even outside a script. Propagation quasi performs some logical deduction, but never conducts any decision which is potentially wrong. So, it reduces the variable domains, but usually does not arrive at a solution where all variables are determined.
Propagation is complemented by search, which is expressed by both the distribution strategy (FD.distribute in your case) and the search engine (e.g. Search.base.one). Propagation and distribution take turns during the search process: whenever no more propagation can happen, the distributor makes a decision. Therefore, it waits until all propagators are finished. This is the waiting behaviour you observed. This is also the reason why the distributor should be at the end of a script.
A particular advantage of the Oz constraint model is that both the distribution strategy and the search engine are programmable by the user. The distribution strategy defines quasi the shape of the search tree and the search engine defines how this search tree is traversed for finding a solution.
Best, Torsten -- Torsten Anders Sonic Arts Research Centre • Queen's University Belfast Frankstr. 49 • D-50996 Köln Tel: +49-221-3980750 http://strasheela.sourceforge.net http://www.torsten-anders.de _________________________________________________________________________________ mozart-users mailing list [email protected] http://www.mozart-oz.org/mailman/listinfo/mozart-users
