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From: kaushik@cpsc.ucalgary.ca (Vinit Kaushik)
Newsgroups: comp.lang.prolog,comp.ai
Subject: Information request for temporal languages.
Keywords: Temporal Logic Programming, Interval Arithmetic.
Message-ID: <2512@cs-spool.calgary.UUCP>
Date: 16 Feb 90 23:04:51 GMT
Sender: news@calgary.UUCP
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Hi. I am doing my MSc in the area of temporal logic programming.
So far I have implemented logical interval-arithmetic for a Prolog
interpreter we have here; this was done in Scheme. With this as a basis,
an interpreter for a new logic programming language called Starlog (designed
by John Cleary) is going to be implemented.
Starlog is Prolog-like. It differs from standard Prolog in the following ways:-
[1] User-defined predicates make use of timestamps to aid their computation
    in terms of clarity and efficiency. Time in Starlog is linear, real
    (hence, infinite) and bounded on both sides of the total ordering.
    Starlog supports only future-directed reasoning.
[2] Program interpretation is done bottom-up via least fixpoint
    computation. The explicit timestamps on user-defined predicates are used
    to schedule clause execution.
[3] All arithmetic variables (including the timestamps) are internally
    represented as intervals of real numbers. Order-independence of goals and
    prevention of (precision) error propagation are achieved by using logical
    interval-arithmetic.
[4] Optimistic distributed or-parallel execution is envisaged based on ideas
    of virtual time (D.R. Jefferson).

	I am currently looking for literature/code regarding available
temporal/constraint-based languages. Any references/suggestions would be
most welcome.

	Vinit Kaushik (kaushik@cpsc.UCalgary.CA)