2025/01/17

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2025-01-18 00:18:48 +0100 <monochrom> And just around the same time in #haskell-offtopic we were talking about how programs come ship with their own C++ libs to avoid DLL hell.
2025-01-18 00:17:58 +0100 <monochrom> You may need more than spelling out a rigorous statement. You may end up also needing to spell out exactly which proof system you chose. Like I said, choosing a different one leads to the opposite result.
2025-01-18 00:16:30 +0100agent314(~quassel@37.19.210.25) agent314
2025-01-18 00:16:06 +0100agent314(~quassel@c-24-17-1-67.hsd1.wa.comcast.net) (Ping timeout: 252 seconds)
2025-01-18 00:13:57 +0100 <monochrom> And whatever you do in model theory, you must respect that Herbrand models are here to stay, even if it may be an annoying silly oddball.
2025-01-18 00:13:42 +0100 <haskellbridge> <thirdofmay18081814goya> i'll be back with a more rigorous statement
2025-01-18 00:12:25 +0100tromp(~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl) (Quit: My iMac has gone to sleep. ZZZzzz…)
2025-01-18 00:12:16 +0100 <monochrom> ... and I guess that's one way to see why there are countable models for ZFC!
2025-01-18 00:11:52 +0100 <monochrom> So for example if you argue that programs are countable, you are just reminding us that the Herbrand model is countable.
2025-01-18 00:11:08 +0100 <monochrom> It is fairly trivial. It's literally the set of ASTs.
2025-01-18 00:10:48 +0100 <monochrom> "It's semantics all the way down" >:)
2025-01-18 00:10:37 +0100 <EvanR> I'll have to look that up and hope it's not ridiculously trivial lol
2025-01-18 00:10:24 +0100 <EvanR> Herbrand
2025-01-18 00:09:59 +0100 <EvanR> when you're dealing with raw data, no IO
2025-01-18 00:09:51 +0100 <monochrom> In particular if you think that you are using merely syntax trees for your argument, then you are choosing the Herbrand model, therefore it's a model, therefore it's also a semantics! There is no escape from arguing semantics
2025-01-18 00:09:43 +0100merijn(~merijn@128-137-045-062.dynamic.caiway.nl) (Ping timeout: 264 seconds)
2025-01-18 00:09:35 +0100 <EvanR> which happens in haskell sometimes
2025-01-18 00:09:22 +0100 <EvanR> and never really refer to any meaning
2025-01-18 00:09:12 +0100 <EvanR> or the logic of how you put the sentences together
2025-01-18 00:08:56 +0100 <EvanR> because you're really talking about the syntax
2025-01-18 00:08:49 +0100 <EvanR> sometimes something can be said about any possible semantics
2025-01-18 00:08:12 +0100 <monochrom> I think both are necessarily semantic. But then that's a tautology. You need to choose a semantic (aka model again) before you can argue anything.
2025-01-18 00:05:55 +0100 <monochrom> You can choose a different level of abstraction (aka model) you get a different conclusion. This is supposed to be normal.
2025-01-18 00:05:34 +0100 <EvanR> uncountable is necessarily semantic
2025-01-18 00:05:15 +0100simplystuart(~simplystu@c-75-75-152-164.hsd1.pa.comcast.net)
2025-01-18 00:05:13 +0100 <EvanR> monochrom, yes that's what I was getting at
2025-01-18 00:04:59 +0100 <EvanR> also there's a difference between computable real and algorithmic real
2025-01-18 00:04:43 +0100 <monochrom> And it is also related to the deal with real numbers, set theory, everything. There are countable models of ZFC, and yet there are also uncountable sets.
2025-01-18 00:04:42 +0100 <geekosaur> hence are countable
2025-01-18 00:04:38 +0100merijn(~merijn@128-137-045-062.dynamic.caiway.nl) merijn
2025-01-18 00:04:37 +0100 <geekosaur> yes
2025-01-18 00:04:26 +0100 <haskellbridge> <thirdofmay18081814goya> geekosaur: the computable reals are embeddable in the naturals!
2025-01-18 00:04:12 +0100 <EvanR> is "x" there a metavariable or literally x
2025-01-18 00:04:06 +0100 <geekosaur> there are countably many values of IEEE float or double, though. you're limited to some form of "computable reals" on any physical computer
2025-01-18 00:03:19 +0100 <haskellbridge> <thirdofmay18081814goya> well if a theory is a set of axioms and derivable sentences, then we should admit such a language (the one having the judgment 'x is a value of type Real Number')
2025-01-18 00:03:02 +0100 <EvanR> usually you need a language for that
2025-01-18 00:02:56 +0100 <EvanR> as far as real numbers go it's a pretty nutty way to specify one xD
2025-01-18 00:02:47 +0100 <monochrom> We know of at least two theories (aka models) of programming, and they disagree on countability as well as other things. The moral is that you choose a theory to suit a purpose, not for Platonic "absolute" "truth".
2025-01-18 00:02:29 +0100paul_j(~user@8.190.187.81.in-addr.arpa) (Quit: Asta la vista)
2025-01-18 00:02:23 +0100 <EvanR> jumping to another level of abstraction, beyond the syntax
2025-01-18 00:02:04 +0100 <EvanR> that's mixing concepts
2025-01-18 00:01:38 +0100 <haskellbridge> <thirdofmay18081814goya> right, e.g. a language with the judgment 'x is a value of type Real Number' does not have countably many statements I think
2025-01-18 00:01:18 +0100simplystuart(~simplystu@c-75-75-152-164.hsd1.pa.comcast.net) (Ping timeout: 244 seconds)
2025-01-18 00:00:52 +0100 <EvanR> haskell being an example of one
2025-01-18 00:00:45 +0100 <monochrom> "I thank GHC for suggesting this newtype."
2025-01-18 00:00:41 +0100 <EvanR> formal languages come with grammar rules which limit you to a countable number of sentences
2025-01-18 00:00:19 +0100 <monochrom> And on second thought, I am not even sure I can take credit. My purpose was to make a newtype to allow the like of (\x -> x x), and the error message literally inspires that definition!
2025-01-18 00:00:01 +0100 <EvanR> countable and constructible is certainly not the same thing
2025-01-17 23:59:57 +0100 <haskellbridge> <thirdofmay18081814goya> I am not convinced there are countably many statements in any mathematical theory
2025-01-17 23:59:36 +0100 <EvanR> which doesn't stop people believing in uncountability