Thematics Of Order -- Discussion
Jon Awbrey
jawbrey at att.net
Mon Apr 18 19:52:21 CEST 2005
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TOO. Discussion Note 4
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AK = Antti Karttunen
JA = Jon Awbrey
Re: TOO-DIS 3. http://stderr.org/pipermail/inquiry/2005-April/002549.html
In: TOO-DIS. http://stderr.org/pipermail/inquiry/2005-April/thread.html#2546
In part:
AK: Inspired by this I propose a more practical question:
Can we find a nice "closed" (or somehow easily computed)
form for:
AK: http://www.research.att.com/projects/OEIS?Anum=A061858
AK: or a similar table involving the differences of ordinary
integer multiplication table and e.g. the mult. table of
GF(3)[X].
JA: I do see the connection you are making with logic ...
AK: No, not really, I wasn't interested about logic when I submitted
A061858 and the related tables and sequences, but instead, I was
intrigued by Frank Ruskey's algorithm for generating irreducible
GF(2)[X] polynomials
AK: see http://www.cs.uvic.ca/~ruskey/Publications/GenIrrPoly.html
and http://www.theory.cs.uvic.ca/~cos/gen/poly.html
I said I saw the connection you were making with logic ---
I didn't say 'you' saw the connection you were making ...
AK: and was then wondering whether there's any reasonable way
to estimate whether an irreducible GF(2)[X] polynomial
(its binary encoding) is also a prime in N. (See:
AK: http://www.research.att.com/projects/OEIS?Anum=A091206
AK: and of course it's here where the carry bits,
those little lice of binary arithmetics come
in picture.
Well, that one makes me scratch my head a little ...
It's still a bit too additive for my present bit
of gnosis-following, but I did spend/waste a lot
of time once thinking about how 1 was the first
imaginary number, as it's a solution to x+1 = 0
in mod 2 arithmetic, the irreducible polynomial
x+1 having a coefficient representation of 11,
which is the prime 3 if you read it in base 2.
And x^2 + 1, whose zeroes are +-i, associates
to 101, which is the prime 5 over base 2.
But I was very young then ---
and so much dimmer now ...
JA: back when we used to call these "mask operations", it was
said that ADD was a combination of XOR plus a shifted AND,
and of course the process would have to be iterated until
it terminated.
AK: This is the item #23 (by Richard Schroeppel) in HAKMEM:
(A AND B) + (A OR B) = A + B = (A XOR B) + 2 (A AND B).
AK: Follow the link in:
http://www.research.att.com/projects/OEIS?Anum=A050600
Thanks for the link, though I'm
sure it is much older than that.
JA: Let me observe, however, that you are still staying largely within
the arena of additive representations, since base representations
are sums of products, or sums of multiples of powers of the base.
Here the main connective is additive, so maybe this would be
roughly analogous to disjunctive normal forms in logic.
AK: I admit that one can find many "rough analogies" between various domains
of mathematics (and maybe life in general...), but as long as they don't
turn out to be real isomorphisms/homomorphisms, I wonder where this kind
of "top-down musing" will eventually lead. I think the real surprises
come from the bottom, small but significant details, after all.
Yes, part of the context on another list that jogged my memory of
these questions, in combination with Leroy Quet's recent messages
on permutational sequences, was the problem of what distinguishes
genuine from specious analogies, with especial reference to those
between logic and math that Leibniz, Boole, DeMorgan, Peirce, and
a host of others were wont (or wanton) to experiement with.
AK: BTW, this reminds me of the simple "binary/quaternary" coding of
the Game Trees (as in the Combinatorial Game Theory) I stumbled
upon a few months ago.
AK: Unfortunately, it doesn't give an isomorphism between
the natural numbers and the equivalence classes of the
game positions in the CGT (e.g. when you collapse various
dominated and reversible positions to the same equivalence
class), although it does filter out multiple occurrences of
the exactly identical branches.
AK: I was wondering whether one could "extend" the CGT-addition
to these game tree codes, so that an addition of two trees,
of which the other or both are "non-canonical", would also
yield a "non-canonical" tree (i.e. the corresponding code).
I will later submit some associated sequences to OEIS,
time permitting.
AK: I include a scanned JPEG-image from the page 40
of 'Winning Ways' as an appendix, with the margin
notes in my bad handwriting ... SeqFan-server will
probably balk.
AK: From those ten examples it should be an easy
exercise to figure the principle of encoding.
AK: Just another proof that there's so many ways of playing
with integers, and their various representations.
Just to continue with the free-associative logics,
there is always a game-theoretic aspect to proofs,
especially with respect to untangling quantifiers,
and one of the things that led me to this present
nexus was looking for multiplicative analogues of
surreal numbers. But I diverge ...
Jon Awbrey
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inquiry e-lab: http://stderr.org/pipermail/inquiry/
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