Timeline for Can infinity shorten proofs a lot?
Current License: CC BY-SA 3.0
6 events
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| Feb 15, 2012 at 17:47 | history | edited | David White | CC BY-SA 3.0 |
Fixed a misspelling
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| Nov 17, 2009 at 22:59 | comment | added | Terry Tao | A related instance would be the existence of normal numbers, just by picking one at random. (It's cheating a little, though, since normality is inherently an infinitary concept.) Another is the existence of non-computable functions from the naturals to the naturals (since there are uncountably many functions, and countably many computable ones), though in this case it's not so hard to finitise the argument. | |
| Nov 17, 2009 at 3:28 | history | edited | Mariano Suárez-Álvarez | CC BY-SA 2.5 |
typo
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| Nov 17, 2009 at 2:57 | comment | added | Richard Dore | The technique of proving that A\B is nonempty because |A| > |B| ought to offer many examples. Anyone have good examples where A is countably infinite, and B is finite but hard to get a concrete bound on? | |
| Nov 16, 2009 at 23:46 | comment | added | gowers | That's a good example, but I think it may already form part of the presentation (when they talk about infinite sets and the work of Cantor). I'll check though. | |
| Nov 16, 2009 at 23:44 | history | answered | Mariano Suárez-Álvarez | CC BY-SA 2.5 |