Path: utzoo!utgpu!attcan!uunet!seismo!sundc!pitstop!sun!quintus!ok
From: ok@quintus.uucp (Richard A. O'Keefe)
Newsgroups: comp.lang.prolog
Subject: Re: sets of integers
Message-ID: <876@quintus.UUCP>
Date: 15 Dec 88 23:52:37 GMT
References: <MATSC.88Dec13114720@skarabe.sics.se>
Sender: news@quintus.UUCP
Reply-To: ok@quintus.UUCP (Richard A. O'Keefe)
Organization: Quintus Computer Systems, Inc.
Lines: 9

In article <MATSC.88Dec13114720@skarabe.sics.se> matsc@sics.se (Mats Carlsson) writes:
>I would like to share a way of representing sets of integers which I
>have found useful in a theorem proving application.  The sets are
>represented as binary trees.

Actually, they are 4-way trees.  The method is a special case of
David H.D. Warren's and Fernando Pereira's "logarithmic arrays" method,
see LOGARR.PL in the DEC-10 Prolog library or library(logarr) in the
Quintus Prolog library.  The tree is just an array of bits.