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From: Abbott@AEROSPACE@sri-unix.UUCP
Newsgroups: net.lang.prolog
Subject: Purity
Message-ID: <12813@sri-arpa.UUCP>
Date: Wed, 19-Oct-83 22:52:00 EDT
Article-I.D.: sri-arpa.12813
Posted: Wed Oct 19 22:52:00 1983
Date-Received: Sun, 23-Oct-83 17:16:22 EDT
Lines: 12

From:  Abbott at AEROSPACE (Russ Abbott)

In considering the question of Prolog's purity vs. its convenience
for programmers, I wonder how '=..' fits in.  As a pure first order
logic system, Prolog disallows variables as predicate names--even
though that would sometimes be very convenient.  Yet one can write

        Term =.. [Predicate | Arguments],
        Term,

in violation of all first order principles.  What are the
justifications for these rules ?