Re: Atomic Structures
Date: Wed, 25 May 2016 15:34:08 -0700 (PDT)
Message-ID: <84a940ea-0b16-431e-801f-e901ddb7f759_at_googlegroups.com>
> I think you will agree that FOPC was the result of Boole and others, and
> Codd created the First, the one and only Relational Algebra.
Here on this site you can find, what George Boole has done: https://www.gutenberg.org/files/15114/15114-pdf.pdf
The RM can not be founded on FOPC. Let me name just a few of the reasons:
1.
I will repeat the following text from my post, because it is important:
So, in simple terms: the predicates are linguistic constructs and predicates
correspond to concepts. Concepts are mental constructs and concepts "make" sets.
However the predicates (concepts) does not identify objects. Note that I wrote above that the extension (set) is an object. As names denote objects then the extension (or set) has a name. As you can see from this text, concepts are dominant, not predicates. Another thing that can be seen from this text is that many objects (entities) are used. I have introduced the theory of identification in which identification of objects play an important role. This further leads to the conceptual level.
In this, very short text; I explained that E. Codd did not understand some important and basic things. Moreover, I have not noticed that Codd wrote something about concepts, relationships between concepts and predicates, concepts and sets, thoughts, relationships between thoughts and language, formal theory of spoken languages, proof theory for propositional logic and predicate logic, the relationship between mind and logic, ...
2.
Here is another reason for the conceptual level:
Kurt Gödel, 1944:
“By the theory of simple types I mean the doctrine which says that the
objects of thought (or, in another interpretation, the symbolic expressions)
are divided into types, namely: individuals, properties of individuals,
relations between individuals, properties of such relations, etc. (with a
similar hierarchy for extensions), and that sentences of the form: " a has
the property φ ", " b bears the relation Rto c ", etc. are meaningless, if
a, b, c, R, φ are not of types fitting together. Mixed types (such as
classes containing individuals and classes as elements) and therefore also
transfinite types (such as the class of all classes of finite types) are
excluded. That the theory of simple types suffices for avoiding also the
epistemological paradoxes is shown by a closer analysis of these. (Cf.
Ramsey 1926 and Tarski 1935, p. 399)."
Note that between terms from this Gödel's text and terms from "entity relationship model", the following links are valid:
“Individuals” = entities
“Properties of individuals” = properties of entities “Relations between individuals” = relationships “Properties of such relations” = properties of relationships
Note that this Gödel's text was written 26 years before RM, 32 years before ER model. Note that this Gödel text is about conceptual level, not about predicates.
Note that a man does not see an object as a collection of molecules, atoms, and sub particles. People do not have the capacity nor do they need something like this. They observe objects as a set of properties - it is by using mental, not by physical means.
3.
As far as I know Codd never mentioned Frege's name. Regarding Predicate
calculus, Codd was writing about his compatriot B. Russell. However, keep in
mind that Frege founded Predicate Calculus. B. Russell has done nothing in
the predicate calculus. So I am not obsessed with Frege. Rather I would say
that I am writing about facts.
As far as I know, Frege experienced personal tragedy. He had two sons, and
they both died. Also Frege's wife died first.(These data should be checked.)
I mean that truth should be said.
Your assertion that Predicate Logic is old 2000 years and begins from
Aristotle is not true. (The same assertion you can find in C. Date books. In
his book “Database in depth” on page 169, he wrote: “Elements of predicate
logic go back well over 2000 years, at least as far as Aristotle (384 - 322
BCE ). But Date does not understand Frege’s Predicate Logic, which is the
real predicate logic.
Aristotle’s predicates are very different from Frege’s predicates. Therefore this claim that today’s Predicate Logic is old 2000 years is heavy disinformation.
4.
We need the conceptual model when we have relationships among entities.
5.
In his paper “Extending the database relational model to capture more
meaning” in section 4, E. Codd introduced “entities”. This imply ER
conceptual model and mapping between ERM and RM.
This Codd’s paper has some mistakes of fundamental character. Given the
enormous importance of the issues that this paper attempts to solves, in my
opinion, the publication of this paper is scandalous. Let me mention just
"invisible surrogate key" and that Codd did not notice the problem of
"history". Work with the mapping between two data models, is not possible
without the solution of the problem known as "history".
> vi.
> >
> What is the truth-value of the following sentence:
>
> This sentence is false.
>
>
> That is the typical behaviour of a sub-human freak; an entertainer; a
> magician, the pig-poop-eaters who write the books that you read. I did
> not expect that from you, Vladimir.
This above sentence is famous. Based on this problem, A. Tarski has started
work on the definition of truth in 1930. In 1950 he did the so-called “truth
in model” and he started one of the most important mathematical theory, it
is Model Theory. Usually the best theorists from database theory are using
the model theory.
Today, semantic (recursive) definition of truth given by A. Tarski, is
generally accepted.
I assume that you are not interested in this topic. With this post I will finish this topic because this is my final opinion.
Vladimir Odrljin Received on Thu May 26 2016 - 00:34:08 CEST