🚀 go-pugleaf

	G'day. I am looking for literature, pointers, tips etc. on
systematic approaches to heuristic search (if such things exist). In
particular, I am interested in the question of what heuristics may be
defined in a given language. The reason I am interested is that when
looking for applications for a deductive database, there are often
occasions when one wants to compute a given subset of the transitive
closure of some relation. For example, when searching for the optimal
flight between places A and B, a naive algorithm would enumerate all
flights and choose the best, whereas a smarter algorithm would have some
way of controlling the search, so that flights which cannot possibly be
optimal are not considered. It seems tempting to define a heuristic as a
way of finding the solutions in a given order without sorting all the
answers (ie so that the order can be computed "on the fly"), but before I
get too carried away I'd like to hear about any previous work in this area.

	An interesting sidelight is that magic sets and the like may be
thought of as an extreme case, in that the pruning strategy of such methods
is complete, ie no solutions are pruned. 

	Over to you. I'll post a summary of any references I get to the
net.

			Thanks in advance, 
					  Cheers,
						 James.