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I deduce you are studying logic (billwadge.wordpress.com)
104 points by akakievich on Sept 30, 2015 | hide | past | web | favorite | 35 comments

You're studying the tautologic that you're studying

Sickeningly, you're studying illogic

You're a circular logician because you're studying circular logic. You're studying circular logic because you're a circular logician.

I realized you'd been studying fridge logic

> I realized you'd been studying fridge logic

If it's appropriate to make a joke, then hopefully it's appropriate to admit not to getting it; and this one defeats me.

Thanks, that clears it up. Weird that they didn't put in a reference to close kin 'staircase wit': https://en.wikipedia.org/wiki/L%27esprit_de_l%27escalier

Bill Wadge is the co-designer of Lucid, the classic dataflow language that Alan Kay, among others, has praised. Lucid seems due for a revival, if not for widespread use, at least for relearning its core ideas.


Lucid was called a dataflow language at one point, but is more accurately an 'eduction' language. The key difference is that Lucid relies on demand-driven evaluation, wheras dataflow semantics entirely relies on the more push-based semantics of data becoming available to fire an operation. I suppose you could call it 'tagged-token demand-driven dataflow', but its semantics are much different from other dataflow languages such as SISAL, VAL or Id.


Prior to meeting you I wasn't too sure, but after our last few conversations I became more and more convinced you study Bayesian statistics.

At first I found this sort of quirky and cool. By the time I got to the end it was full on laughing-out-loud. This is pretty darned funny....

Studying mathematical logic is tough on your social life: you're either missing out or failing.*

* Goedel incompleteness theorem

Since you are a student of logic, but you're not studying logic, I deduce that you are and aren't studying paraconsistent logic

(No, really! See: http://www.iep.utm.edu/para-log/ )

It would be interesting to see these phrases translated into other languages. Greek, for one, or an analytic language such as Mandarin. Is it possible for the sentences to still make sense, or even retain the humor?

Συμπεραίνω πως σπουδάζεις λογική. Πιστεύω πως σπουδάζεις δοξαστική λογική. Γνωρίζω πως σπουδάζεις γνωσιολογική λογική. Υπάρχει πιθανότητα να σπουδάζεις πιθανοθεωρητική λογική. Έχεις σπουδάσει χρονική λογική. Κατά 73% σπουδάζεις ασαφή λογική. Σπουδάζεις παρασυνεπή λογική και δε σπουδάζεις παρασυνεπή λογική. Είναι πιθανό πως σπουδάζεις τροπική λογική. Πιθανόν ίσως μπορεί να σπουδάζεις πολυτροπική λογική. Δεν δεν σπουδάζεις διαισθητική λογική. Σπουδάζεις γραμμική λογική, σπουδάζεις γραμμική λογική. Παρατήρησα πως σπουδάζεις κβαντική λογική. Έχω αδιάσειστα στοιχεία πως σπουδάζεις εποικοδομητική λογική. Ένα από τα πράγματα που κάνεις είναι σπουδές λογική δευτέρου βαθμού. (συνδιαστική λογική) σπουδάζεις. Φαίνεσαι προβληματισμένος, μάλλον σπουδάζεις απαγωγική λογική. Σπουδάζεις και το αντικείμενο είναι μοναδική λογική. Το αρνείσαι, αλλά λέω πως σπουδάζεις διαλεκτική λογική.

I'm not sure which way the comments went, but there are some that appear both here and there. One doesn't seem to have popped up here, but is so good that I must repeat it (it's not mine!):

> That thing that you are studying… we call it denotational logic. > - JoshH (https://billwadge.wordpress.com/2015/09/30/i-deduce-you-are-...)

Here's a few off the top of my head :)

- I'm studying logic and I'm not studying logic. Boom. [1]

- Since my logic has one more element than your logic, I'm studying second-order logic. [2]

- You're studying non-monotonic logic, but I could be wrong. [3]

[1] Principle of Explosion.

[2] Unbounded counting can't be expressed in first-order logics.

[3] http://plato.stanford.edu/entries/logic-nonmonotonic/

The sort of logic you are studying is order-sorted logic, which is a sort of first-order logic with predicates.

You are studying science fiction logic aboard a spaceship moving at warp speed, with a clone of yourself who looks like you yet was born yesterday, but both of you are having some trouble concentrating because your faster-than-light vessel is getting hit by laser bolts fired by humanoid aliens.

Is there a good book that surveys most of the logics mentioned in the articile? I only know of books that go deep in one or two of these logics (e.g., predicate calculus, fuzzy logic), but haven't seen a resource that surveys all (or a good number) of them. Any recommendations?

Stanford Encyclopedia of Philosophy: http://plato.stanford.edu/search/searcher.py?query=logic

You cannot study this kind of logic.

I think Godel may have disproved you on that.

Pretty sure the incompleteness theorem doesn't enable one to study things one cannot study. (eg imagine a logic for which one could not write down the axioms but was nonetheless 'consistent' by some external measure)

Yeah, but you made a statement about the kind of logic you cannot study, so we can begin by formalizing that.

I suppose an easy way out is to show that such a thing cannot exist in the way that other mathematical structures exist, trivially showing that you have studied all of it that there is(n't) to study.

Perhaps "Given what I've seen you up to, I can personally grasp that you're studying intuitionistic logic.".

Or, "I can prove that you are studying intuitionistic logic."

Man, half of these left me laughing but the other half flew pass my head.

Are there any good resources on logic?

The Stanford Encyclopedia of Philosophy; this article is a perfect start: http://plato.stanford.edu/entries/logic-classical/

Of course, this is extremely dense! A book that covers this article in a pedagogical and beautiful manner is A Mathematical Introduction to Logic by Enderton.

But still, this is all formal logic. It lies at the locus of many disciplines and ways of thinking, and there are many, many formal logics to explore. It is the idea of formal logic which is important, and the SEP is a good place to put it in context.

Well that's just classical logic, which is pretty much what you expect when you hear the word logic ('False AND True = False', etc) the other ones were developed to address it's shortcomings and paradoxes.



Of course, but the most well developed theory pedagogically and theoretically is first order classical logic. So, it's the best place to learn all of the standard concepts like derivability, completeness and soundness theorems, and all of that jazz. That's how I learned it and then my interests soon turned to intuitionistic logics and type theories. Still, the metatheory is very similar and the metatheoretic differences between logics are often framed as deviations from the metatheory of first order classical logic.

And classical logic is the one used in mathematics (and methatheories) because those are the most useful axioms in that setting. (would you agree that's a fair statement?)

For example, it's not useful to think an equality has 30% chance of being true, or not having a truth value, and so on. It allows building structure on solid foundations.

I think intuitionistic logic is just as valid a foundation for mathematics as classical logic. They both have very attractive features for mathematics. They both appeal to different intuitions about what logic ought to be. When it comes to mathematics, one is more natural than the other in different contexts.

The proof theory of a logic is what is useful to mathematics. It's hard to beat either classical or intuitionistic first order logic when it comes to their proof theories. I think that's why nothing else really catches on. You can build other logics on top of one or the other anyway. Another perspective is that you can encode other logics in them.

You are studying Boolean logic, xor you are not studying Boolean logic.

It is not the case that you both are, and are not, studying constructive logic.

I study ontology, therefore I am.

Never mind true or false, it is completely irrelevant that you are studying ternary logic.

edit to add -

I can imagine an even greater being studying ontological logic.

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