2026/01/15

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2026-01-15 23:42:08 +0100 <dolio> Yeah.
2026-01-15 23:42:03 +0100tomsmeding. o O ( every _computable_ enumeration -- that bit is relevant here )
2026-01-15 23:41:34 +0100 <EvanR> jreicher, I went over that in a few ways above
2026-01-15 23:41:05 +0100 <EvanR> a proof is worth 1000 words
2026-01-15 23:41:00 +0100 <dolio> Cantor's diagonal argument shows every computable enumeration of the computable bit streams misses a computable bit stream.
2026-01-15 23:40:55 +0100 <jreicher> "computable" can be understood as "generated by a program", and all program texts are finite. So the set of all program texts is countable, and so is the set of computable outputs
2026-01-15 23:40:45 +0100 <EvanR> at some point doing the proof might help since this is ... mathematical
2026-01-15 23:40:24 +0100 <dolio> No, it isn't.
2026-01-15 23:40:15 +0100 <jreicher> And if you only have the computable ones, the set is countable.
2026-01-15 23:39:04 +0100 <dolio> They aren't. We only need the computable ones.
2026-01-15 23:38:52 +0100 <EvanR> at that time, it wasn't appreciated the subtleties that binary streams created for defining reals... but a stream of bits is pretty simple
2026-01-15 23:38:44 +0100merijn(~merijn@host-cl.cgnat-g.v4.dfn.nl) merijn
2026-01-15 23:38:42 +0100 <jreicher> dolio: Ok, I'll stick to bistreams. In what way is a non-computable (infinite) bitstream "constructive"?
2026-01-15 23:38:22 +0100 <monochrom> I think GCC for DOS could do 32-bit in real mode. I forgot. But just do whatever GCC-for-DOS does.
2026-01-15 23:38:21 +0100 <jreicher> To begin with I'm pretty sure he was
2026-01-15 23:38:18 +0100 <dolio> Even though the bit streams are uncountable.
2026-01-15 23:38:10 +0100 <EvanR> was cantor even talking about real numbers
2026-01-15 23:38:06 +0100 <dolio> It's actually possible for the (Dedekind) reals to be countable in constructive mathematics.
2026-01-15 23:38:04 +0100 <EvanR> yes that is what this whole discussion is about
2026-01-15 23:38:01 +0100 <jreicher> (Maybe I've misunderstood the idea)
2026-01-15 23:37:56 +0100 <jreicher> EvanR: how can you have Cantor's diagonalisation without the reals?
2026-01-15 23:37:33 +0100 <EvanR> lol
2026-01-15 23:37:31 +0100 <dolio> jreicher: Like 0.11111... = 1.0 (binary).
2026-01-15 23:37:30 +0100int-eruns
2026-01-15 23:37:28 +0100 <int-e> (so *now* we're getting off topic, huh)
2026-01-15 23:37:16 +0100 <EvanR> which isn't about them
2026-01-15 23:37:10 +0100 <EvanR> we're getting off topic trying to jam classical reals into the discussion
2026-01-15 23:37:08 +0100 <int-e> dolio: Don't you like Dedekind cuts?
2026-01-15 23:36:57 +0100 <jreicher> Huh?
2026-01-15 23:36:44 +0100 <dolio> Reals are a quotient.
2026-01-15 23:36:42 +0100target_i(~target_i@user/target-i/x-6023099) (Quit: leaving)
2026-01-15 23:36:40 +0100 <jreicher> Sorry, I should say ALL the infinite bitstreams
2026-01-15 23:36:36 +0100 <monochrom> (Oh then it probably also runs on 8088 DOS too...)
2026-01-15 23:36:33 +0100 <int-e> monochrom: protected mode or real mode?
2026-01-15 23:36:32 +0100 <jreicher> If you have infinite bitstreams, you have all the reals
2026-01-15 23:36:18 +0100 <dolio> Reals are too complicated to get into. This is just the bit streams.
2026-01-15 23:36:12 +0100 <monochrom> OK OK April's Fool project: Drastically overhaul GHC to be runnable on 286's segment model!
2026-01-15 23:36:03 +0100 <int-e> (It does seem rather unlikely though.)
2026-01-15 23:35:56 +0100 <EvanR> who ordered reals
2026-01-15 23:35:44 +0100 <int-e> I don't know that there never was a 16 bit version of GHC.
2026-01-15 23:35:43 +0100 <jreicher> dolio: I think you're presupposing that the set of reals is "constructive". No?
2026-01-15 23:35:24 +0100 <monochrom> Because AFAIK GHC assumes a flat/linear 32-bit addressing model i.e. at least 386.
2026-01-15 23:35:22 +0100 <dolio> jreicher: I don't understand the question.
2026-01-15 23:35:12 +0100 <EvanR> "wavfunction collapse procedural generation" of anecdotes xD
2026-01-15 23:34:42 +0100 <monochrom> Heh
2026-01-15 23:34:36 +0100 <int-e> monochrom: I don't know. I'm filling in my own details here :P
2026-01-15 23:34:19 +0100 <jreicher> OK. But what about the set he's diagonlising?
2026-01-15 23:34:15 +0100 <monochrom> s/does that you/does that mean/
2026-01-15 23:34:05 +0100 <monochrom> Wait, does that you use a 286 to emulate a 386 then run GHC there?
2026-01-15 23:33:58 +0100 <dolio> jreicher: Cantor's diagonal argument is constructive. It's basically what I linked. Given `enum : ℕ → (ℕ → 2)`, one can construct a `ℕ → 2` that is not in the image of `enum`.