[comp.lang.prolog] PROLOG Digest V4 #81

PROLOG-REQUEST@SU-SCORE.ARPA (Chuck Restivo, The Moderator) (12/03/86)

PROLOG Digest            Thursday, 4 Dec 1986      Volume 4 : Issue 81

Today's Topics:
                        Announcement - Thesis,
                    LP Library - PDProlog & Update
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Date: Wed, 3 Dec 86 13:14 EST
From: Tim Finin <Tim@cis.upenn.edu>
Subject: Defense

                         Dissertation Defense
                   Computer and Information Science
                      University of Pennsylvania

       A HIGHER-ORDER LOGIC AS THE BASIS FOR LOGIC PROGRAMMING

                           GOPALAN NADATHUR
                       (gopalan@cis.upenn.edu)


The objective of this thesis is to provide a formal basis for 
higher-order features in the paradigm of logic programming.  Towards 
this end, a non-extensional form of higher-order logic that is based 
on Church's simple theory of types is used to provide a generalisation
to the definite clauses of first-order logic.  Specifically, a class 
of formulas that are called higher-order definite sentences is 
described. These formulas extend definite clauses by replacing 
first-order terms by the terms of a typed lambda calculus and by 
providing for quantification over predicate and function variables.  
It is shown that these formulas together with the notion of a proof in
the higher-order logic provide an abstract description of computation 
that is akin to the one in the first-order case. While the 
construction of a proof in a higher-order logic is often complicated 
by the task of finding appropriate substitutions for predicate 
variables, it is shown that the necessary substitutions for predicate 
variables can be tightly constrained in the context of higher-order 
definite sentences. This observation enables the description of a 
complete theorem-proving procedure for these formulas.  The procedure 
constructs proofs essentially by interweaving higher-order unification
with backchaining on implication, and constitutes a generalisation to 
the higher-order context of the well-known SLD-resolution procedure 
for definite clauses.  The results of these investigations are used to
describe a logic programming language called lambda Prolog.  This 
language contains all the features of a language such as Prolog, and, 
in addition, possesses certain higher-order features.  The uses of 
these additional features are illustrated, and it is shown how the use
of the terms of a (typed) lambda calculus as data structures provides 
a source of richness to the logic programming paradigm.

Thesis Supervisor: Dale Miller

Committee: Tim Finin, Jean Gallier (Chairman), Andre Scedrov, Richard 
Statman

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Date: 7 Nov 86 23:25:46 GMT
From: David Fiore <ucdavis!ucrmath!hope!fiore@ucbvax.Berkeley.EDU>
Subject: PD PROLOG

This is in response to all the letters I have recieved requesting PD
PROLOG.  I have had very little luck responding to the letters, much
less getting copies of PD PROLOG to those that wanted it.  I am
therefore submitting for the second time a copy of PD PROLOG in 
uuencoded format to the Digest.

Good luck with the program!

-- David Fiore
   UseNet : ...!ucdavis!ucrmath!hope!fiore
   BITNET : consult@ucrvms

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Date: Wed 3 Dec 86 11:25:01-PST
From: Chuck Restivo  <Restivo@Score.Stanford.EDU>
Subject: PDProlog

[cwr]

I left the following files in SCORE:'s Prolog directory.  You'll
need these to use PDProlog.

   PS:<PROLOG>
 PDPROLOG.CODE.2;P775252   75 189686(7)   3-Dec-86 11:14:13 RESTIVO
   .DOCUMENTATION.2;P775252  24 61299(7)  3-Dec-86 11:15:14 RESTIVO
   .HELP.1;P775252          1 711(7)      3-Dec-86 11:08:41 RESTIVO
   .UUDECODE.2;P775252      3 5560(7)     3-Dec-86 11:18:03 RESTIVO
   .UUENCODE.2;P775252      2 4872(7)     3-Dec-86 11:18:59 RESTIVO

-- ed

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End of PROLOG Digest
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