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Tupper's Self-Referential Formula

25 points| guava | 11 years ago |mathworld.wolfram.com

12 comments

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[+] cousin_it|11 years ago|reply
Sorry, it ain't self-referential unless it draws the picture around (0, 0).

I have no idea if that's possible, though. Quines are possible in many programming languages, but the "language" of formulas without quantifiers is very limited. You can encode boolean logic, not sure about loops.

EDIT:

After some Googling, I've found a true self-referential formula: http://jtra.cz/stuff/essays/math-self-reference/index.html

Note that it involves a recursive function definition, and part of the formula is generated by a fixpoint trick. I suppose that's the simplest way to do this.

Also I really enjoyed the way he embedded a watermark into the formula, in a way that's difficult to remove if you don't know what you're doing.

[+] userbinator|11 years ago|reply
Quines are possible in compression algorithms too: http://research.swtch.com/zip

Combining that with a self-referential formula could conceivably lead to something like a formula that generates a compressed zipfile, whose contents are a bitmap image of the formula...

[+] xamuel|11 years ago|reply
Self-referential formulas (truly self-referential ones, not involving the magic constant in Tupper's famous one) are conceptually a consequence of Kleene's recursion theorem, just like self-printing programs, but with a bit more caveats---obviously necessary caveats since it all depends on things like font choice etc. I spelled the details out in a paper [1] but there's really nowhere appropriate to publish it, since it's too trivial for a mathematician/computer scientist audience and too tricky for a more general audience.

[1] http://semitrivial.com/papers/eqn.pdf

[+] netrus|11 years ago|reply
2^(106*17) only has 543 decimal-digits. So with a high likelyhood, the formular will plot "this is so wrong" in several basic fonts and languages for smaller n's as an input.
[+] virtualSatai|11 years ago|reply
You have a pixel grid of 17 x 106, anything you want to drawn in it can be.

To draw an arbitrary figure do this: Start with the pixel in the lowest left corner, if black put 1 as the first digit of a binary number else put 0, then continue first up then one right, the down. Convert this (1802 digit) binary number to decimal and use it as input for the function and there it is.

[+] netrus|11 years ago|reply
Hm, to me this feels scammy, like the 'my-crack-is-nothing-but-the-32894239487th-prim'-trick. Count me impressed as soon as the plot also contains the input range ;)
[+] raldi|11 years ago|reply
A true quine graph would have to include the "N" constant, too.
[+] alexdowad|11 years ago|reply
How did "Tupper" figure this formula out??? Brute force?
[+] andrelaszlo|11 years ago|reply
Nope!

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