Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rochester!daemon
From: miller@CS.ROCHESTER.EDU (Brad Miller)
Newsgroups: comp.lang.prolog
Subject: Re: different Prologs?
Message-ID: <1989Oct17.170152.1192@cs.rochester.edu>
Date: 17 Oct 89 17:01:52 GMT
Sender: daemon@cs.rochester.edu (Old Scratch)
Organization: University of Rochester Computer Science Department
Lines: 18

[]

    Date: 17 Oct 89 09:40:15 GMT
    From: goldfain@osiris.cso.uiuc.edu

    I think the general approach to parallelism in Prolog is somewhat incompatible
    with this idea - all promising approaches are being explored, so an
    intelligent backtrack would never be involved.  

Consider the case where a proof deep in the tree (admitably in parallel)
identifies a culprit high up in the tree. You want to prune the tree and
kill off all the processes currently exploring proofs in that part of the
tree, freeing them up as a resource for exploring other branches.

Proof cacheing probably buys you more in most cases than intelligent
backtracking, but that's another case where [member ?x (:A :A :A)] would
only succeed once. (Sorry for the Rhet syntax :-); I'm sure the translation
is obvious).