Re: W3C RIF: "recursive rules" vs "recursive terms"

Francis McCabe <frankmccabe@sandsoft.com> wrote:
> 
> The issue with running out of memory speaks to a couple of core  
> differences between PRR-based systems and LP-based systems. The most  
> obvious is, of course, the forward-chaining vs backward chaining. A  
> more subtle, but perhaps more significant difference is in the way  
> disjunction is handled.

Many years ago I stumbled upon a CLIPS manual where it was described how to
avoid computing the entire model. It was essentially a description of a
rudimentary Magic Set transformation.  The date on that manual was 1983 or
1984 - a year or two before the first magic set paper appeared.

The point is that one can write bad rules bottom up or top down - doesn't
matter. You can avoid computing the entire model, using smart techniques. That
CLIPS manual author of > 20 years ago was definitely very smart. Too bad he
didn't think that his trick was worth a publication :-)


	--michael