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Re: [ontolog-forum] Data & Relations

To: ontolog-forum@xxxxxxxxxxxxxxxx
From: John F Sowa <sowa@xxxxxxxxxxx>
Date: Thu, 30 May 2013 23:40:58 -0400
Message-id: <51A81BCA.9000403@xxxxxxxxxxx>
Kingsley, David, and John,    (01)

The summary I wrote in my previous note is similar to some of the
techniques I am using in a forthcoming book.  My target date for
finishing it is the end of 2013, and it should be available in
early 2014.  Following is the preface and table of contents:    (02)

    Patterns of Logic and Ontology    (03)

The tutorial I presented as the Semantic Technology Conference in
San Francisco last year covers some of the material in the book:    (04)

    Knowledge Design Patterns    (05)

Some comments on the comments on this thread:    (06)

>> For graphs, I do *not* recommend that you use RDF or even N3 or Turtle.
>> Instead, I suggest E-R diagrams for the entity types and relations.    (07)

> Actual notations for encoding machine readable structured data always
> come into play much later.    (08)

In the Plo book, I use a variety of notations, but I always present
a mapping of each formula or diagram to a statement or statements
in controlled English.    (09)

>> it's *much* easier to say that ∃ means "there exists something
>> of the given type" than to explain what blank nodes mean in RDF.    (010)

> I stay away from blank nodes for these kinds of presentations.
> Basically, blank nodes and reification serve important purposes
> that are only appreciated if comprehension is established.    (011)

Since I emphasize the mapping to and from controlled English,
an existential quantifier (or blank node) is very easy to explain.
It's just a reference to something by saying "a cat" instead of
saying "the cat Yojo".    (012)

If you know that Tom and Sue are siblings, you know that they
have at least one common parent.  But you don't know the identity.
So you need an existential quantifier (or a blank node in RDF).    (013)

> I'm quite sure IMS's DL/1 is not SQL.    (014)

IMS is usually called a "hierarchical DB".  Its basic organization
is a tree, but it allows cross-links to give the effect of a network.
But if you're processing data by going down through the tree, IMS was
very efficient.    (015)

Ted Codd at IBM proposed the relational "model" for databases.
Other groups at IBM Research implemented System/R as an RDB
and developed SQL as a query language.  But the IMS group
at IBM blocked any attempt to make it a product.    (016)

So a little start-up company called Oracle implemented SQL
from the spec's published in the IBM Journal of R & D.    (017)

> I noticed your use of Person:"Kingsley Idehen" .... I'm curious:
> is this a new notation for you?    (018)

I used it for conceptual graphs in 1976:    (019)

    Conceptual Graphs for a Data Base Interface    (020)

> Are there (other) precedents for it you know of?    (021)

There are similar conventions in many programming languages.    (022)

John    (023)

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