Chris Croughton <chris@keristor.net> writes:
> On Tue, 9 May 2006 20:26:30 -0400, Pavel314
> <Pavel314@NOSPAM.comcast.net> wrote:
> More to the point, the rest of us have limited fonts as well (I would be
> surprised if Unicode doesn't have the backward E and upside-down A, but
> I don't have any font which could cope).
Try looking at LaTeX (actually TeX, but LaTeX is a much easier to
manage subset of the TeX language). It was designed for creating print
ready documents and is the standard tool for mathematicians
typesetting equations, papers and documents. It's generally not
WYSIWYG, but when combined with the emacs editor and specific LaTeX
packages, you can get a very powerful document and equation editor.
Although this doesn't help in the general case of writing by everyone,
it does help in the specific case of creating documents for reading by
others.
>> Google "universal quantifier" to get some links to the
>> subject. I remember doing lots of fun things with these. For example, your
>> statement might translate as:
>>
>> A(x) [ RV(x) ==> BI(x) & BL(x) ] ==> E(x) [ BI(x) & BL(x) & RV(x) ]
>
> The sad thing is that I read that straight off and understood it, and I
> haven't done symbolic logic for almost 30 years. It seams that I do
> still use it internally even though I've forgotten most of the names of
> things (I am frequently annoyed at the number of people who think that
> [A => B] => [B => A])...
>
>> There were formal rules for manipulating the quantifiers and qualifiers,
>> most of which I've forgotten long ago. Try asking for help on sci.logic or
>> sci.math.symbolic.
Pick up a book discreet mathematics, they cover all of these things
and they are pretty cheap since they're a standard course in most
science curriculums.
> Converting a natural language into symbolic logic, which seems to be
> what the OP is wanting to do, is however not generally possible. In
> natural language it is possible, even easy, to say things which make no
> sense, like the canonical "This sentence is a lie" which caused a lot of
> computers in Star Trek to blow up, which are not possible to express in
> symbolic logic without an obvious error. And there are ambiguities like
> "time flies like an arrow" which can't be parsed mechanically without
> extra information (although not all languages are as bad, that phrase in
> an inflected language like Latin is not ambiguous).
Yes, it's very easy to create meaningless (as in having no true or
false value) sentances using any language (even symbolic logic and
mathematics). Mathematics is about finding and eliminating those
practices in the search of obtaining 'truth' (or at least truthful
axioms from which a 'real' version of truth can be built). Of course,
there is always a measure of faith (see Godel's Incompleteness
Theorem, The Halting Problem, or the various other limits to logical
truth and knowledge that have been found in other fields of study)
that is required before truth is accepted though, so really, nothing
can be proven to be true.
--
burton samograd kruhft .at. gmail
kruhft.blogspot.com www.myspace.com/kruhft metashell.blogspot.com
|
|