From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00,
	REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4
X-Google-Thread: 103376,d85ddda7d974176
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news2.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!newsfeed00.sul.t-online.de!t-online.de!newsfeed.icl.net!newsfeed.arcor.de!newsspool4.arcor-online.net!news.arcor.de.POSTED!not-for-mail
From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: MI Hownotto by Betrand Meyer
Newsgroups: comp.lang.ada
User-Agent: 40tude_Dialog/2.0.15.1
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Reply-To: mailbox@dmitry-kazakov.de
Organization: cbb software GmbH
References: <1gg01bv89foip.16h83zektx82y.dlg@40tude.net>
 <mailman.19.1162093347.4389.comp.lang.ada@ada-france.org>
Date: Sun, 29 Oct 2006 15:19:46 +0100
Message-ID: <18k8q2n1q72vw.me1gwhq3thhd.dlg@40tude.net>
NNTP-Posting-Date: 29 Oct 2006 15:19:46 CET
NNTP-Posting-Host: 70e49a9c.newsspool4.arcor-online.net
X-Trace: 
 DXC=G2R5;CABW1RPU8j_I0DN6_4IUK<Cl32<Q4Fo<]lROoRQ4nDHegD_]RU[h\lHE9_Y^ZDNcfSJ;bb[UIRnRBaCd<M^OVP3?[ooT7VbT[785A?S6T
X-Complaints-To: usenet-abuse@arcor.de
Xref: g2news2.google.com comp.lang.ada:7260
Date: 2006-10-29T15:19:46+01:00
List-Id: <comp.lang.ada>

On Sun, 29 Oct 2006 06:39:07 +0300 (MSK), Alexander E. Kopilovich wrote:

> Dmitry A. Kazakov wrote:
> 
>> But what were an alternative to MI?
> 
> Perhaps a proper alternative to MI may be a set of different kinds of MI (each
> equipped with its own name) instead of a single notion overloaded with complex
> rules.
>
> Look at algebra for a good example: there we have different compositions of
> two algebraic objects - direct sum, direct product, tensor product etc.
> Mathematicians do not try to pack all those things into one overcomplicated
> notion for everyday use.

To me these refer to just one case, which is already handled quite well.
That's when the structure of inheritance is a DAG. [ OK, there are minor
naming problems, but mathematicians are accustomed to extremely hairy
notations. (:-)) ]

Mathematical structures are simple (I don't mean the sematic of) comparing
with ones found in programming. The reason is that the declarative
framework of a programming language surpasses human's abilities by margin.
This allows us to construct things, which nobody could understand in all
necessary details if they were just written on paper.

Surely a study of algebraic properties of type structures is necessary.
However I don't think it would leave us with a smaller number of cases.
Group theory is an example, that this need not to happen. I think we will
end up with far more complex things than diamond diagram.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de