From mboxrd@z Thu Jan  1 00:00:00 1970
To: 9fans@cse.psu.edu
Subject: Re: [9fans] correcting old failures, and NJ vs MA
From: forsyth@caldo.demon.co.uk
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Message-Id: <20011009214140.3761B199BF@mail.cse.psu.edu>
Date: Tue,  9 Oct 2001 22:44:28 +0100
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>>finally, as forsyth points out, questions of "completeness and correctness"
>>are most often self-assesment exercises. particularly correctness, when
>>designing or building something new. who's to say what the "correct"
>>behaviour of mv/rename in Plan 9 is (well, when it was being designed)?

i was really referring, slightly sarcastically, to the assessment of the `Cambridge' approach
as having such-and-such splendid characteristics as opposed to the `NJ' approach
when i might just as easily have changed the assignment of attributes to each camp,
for much the reasons that anothy suggests (if you aim for simplicity,
a closer approximation to correctness often follows, for instance).
unfortunately, it seems nothing can save us from the new camp, W3C and XML.

as regards the comment above, my prejudice is that `completeness' and
`correctness' (with respect to a specification) have meaning in
mathematics, and that places some bound on our sloppiness, even in
computing.  doing mathematics isn't purely formal, pace Hilbert, but
it isn't arbitrary either.  deciding the specification might well be
subjective, although there are often external constraints on its
choice (eg, it's usually bad for a computer-controlled train to leave
the ground, maglev systems and the like excepted, but it's expected of
computer-controlled airplanes).  having settled on a target, though, i
can make a reasonable attempt to decide whether i've hit it.