Hugh Perkins wrote: > There's a good tutorial on pruning at: > > http://www.cs.nott.ac.uk/~gmh/book.html > <http://www.cs.nott.ac.uk/%7Egmh/book.html> (Section "Slides", number 11) > > In general, I find this kind of stuff really hard to avoid... :-S > ...and indeed, countdown was what I was attempting to solve... o_O