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Path: utzoo!lsuc!dave
From: dave@lsuc.UUCP (David Sherman)
Newsgroups: net.lang.prolog
Subject: Re: "assert" considered harmful?
Message-ID: <1267@lsuc.UUCP>
Date: Sat, 28-Jun-86 23:25:28 EDT
Article-I.D.: lsuc.1267
Posted: Sat Jun 28 23:25:28 1986
Date-Received: Sat, 28-Jun-86 23:57:57 EDT
References: <561@zaphod.UUCP>
Reply-To: dave@lsuc.UUCP (David Sherman)
Organization: Law Society of Upper Canada, Toronto
Lines: 23
Summary: time

In article <561@zaphod.UUCP> bobd@zaphod.UUCP (Bob Dalgleish) writes:
>Adding time into the database should not be that difficult, since it is
>expressed as:
>
>known_controls(Time,Taxpayer1,Taxpayer2) ...
>
>When the time is unknown or irrelevant for the period of interest,
>express it as a construct that matches all time (i.e., a variable).

That's fine for a single statement. But for the definition of the
various rules which apply to corporate reorganizations, we need to
know whether a particular fact is true at a given time, which is unlikely
to coincide with any specific time specified as a fact. Getting this
to work require something along the lines of Kowalski's "holds"
formulism, as best I can figure out.  (That is, make the statement
holds(fact(..., ...), timeN), and assume that unless it's been terminated,
the fact is true at any time after timeN.)

Dave Sherman
The Law Society of Upper Canada
Toronto
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{ ihnp4!utzoo  pesnta  utcs  hcr  decvax!utcsri  } !lsuc!dave