Re: The Real Ideological Root of Terrorism DARWINISM AND MATERIALISM

In article <dfj235$1po8$1@xxxxxxxxxxxxxxxxxxxx>,
John Wilkins <john@xxxxxxxxxxxxx> wrote:

> shane wrote:
> > John Wilkins wrote:
> >
> >
> >>shane wrote:
> >>
> >>
> >>>John Wilkins wrote:
> >>>
> >>>
> >>>
> >>>
> >>>>shane wrote:
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>>Robert J. Kolker wrote:
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>>shane wrote:
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>>Lets not discount the possibility he is both.
> >>>>>>
> >>>>>>
> >>>>>>Inclusive OR. Standard mathematical terminology.
> >>>>>>
> >>>>>>Bob Kolker
> >>>>>>
> >>>>>
> >>>>>
> >>>>>Apologies Bob, I am only a Boolean Algebra man and was taught to be
> >>>>>specific in such matters.
> >>>>>
> >>>>
> >>>>OR is inclusive in Boolean algebra too, I thought.
> >>>>
> >>>
> >>>
> >>>There is also an Exclusive OR and I was taught to always be particular
> >>>in specifying, in order to avoid confusion.
> >>>
> >>
> >>Do you mean XOR in computing? Boole himself specified that OR was
> >>inclusive.
> >>That is, he used the sign + to stand for "and" and "or" (Laws of Thought,
> >>p33). Boolean algebra is regarded as the logical system Boole specified,
> >>although the modern terms rely more on the symbolic logic of Frege and
> >>later.
> >>
> >
> >
> > All that is way over my head, I just learnt enough to decipher the logic
> > programs (and documentation) that were used to control the brewing
> > process where I work.
> >
> A noble task indeed, ensuring that beer is properly brewed (I take it you
> don't work for Carlton, Castlemain or Toohey's then?).
>
> Boolean logic is a two-valued (on-off, true-false) logic developed in 1854 by
> the Rev. George Boole in the cited book.
>
> It lends itself well to digital computers, and of course was so employed by
> the early programmers. The sorts of things you are used to seeing in computer
> prgramming languages, with OR and XOR and so on, were developed much much
> later (in the 1960s, if I recall correctly), and called "Boolean algebra",
> but
> in fact they are just Boolean *logic*.. The algebra is what Bob was referring
> to above. It is standardly written in the form of symbolic logic - OR is
> signed by what is called a "vel", and looks like a sans serif lower case "v".
> It is inclusive. In formal logic, to express an exclusive OR, you have to
> specify:
>
> (A OR B) AND NOT (A AND B)
>
> or the equivalent symbolism. In other words, XOR is a complex operator, while
> OR is a primitive one. So when you use OR in those contexts, it is always
> assumed to be inclusive...

Only by definition. One could start the subject by defining XOR and then
deriving OR.

(A or B) def (A xor B) xor (A and B)

So the same algebra can be built from 'and' and 'xor', in fact one can
do negation in of xor

not A def A xor T

--
Guns don't kill people; automobiles kill people.

.

Relevant Pages

  • Re: The Real Ideological Root of Terrorism DARWINISM AND MATERIALISM
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  • Re: Towards a Formula for Primes
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