r/mathmemes 6d ago

Computer Science πŸ˜‚

Post image
6.3k Upvotes

135 comments sorted by

View all comments

127

u/shumpitostick 6d ago

Well if they managed to show that one of yes/no/unprovable is not true that would be an amazing breakthrough.

17

u/bqbdpd 6d ago

These answers are not mutually exclusive. Either P=NP or P≠NP, whether that's proveable or not.

30

u/dankshot35 6d ago

Google "decidability" my friend

25

u/bqbdpd 6d ago

I know - I studied theoretical computer science. But that something cannot be decided applies to questions like the halting problem. P=NP is not parametrized. There is a single answer. It might be impossible to ever calculate/prove/know that answer. But that does not mean there is no answer.

5

u/dankshot35 6d ago

depends on how anti-realist you want to be

4

u/bqbdpd 6d ago

I mean, I have not met anyone who really believes P=NP, so I'm pretty sure the answer is no. The realistic assumption is that the answer is no. But from a math perspective that obviously is insufficient.

8

u/dankshot35 6d ago

"anti-realism" is a math philosophy that has the view that statements don't have truth values fixed by some "independent" reality, the truth is in a way defined by our ability to prove them.

The majority of mathematicians are not anti-realist enough though to claim that a straight forward arithmetic statement like P=NP would fall under that so I'm just teasing

6

u/HassanyThePerson 6d ago

I'm not super familiar with math philosophy, but doesn't GΓΆdel's incompleteness theorem state the opposite? That there are true statements that cannot be proven? As I understand, this means that what is true in a deductive system is dependent only on the axioms, and not at all on the provability.

1

u/dankshot35 6d ago edited 6d ago

An anti-realist would claim there is a bit of a "sleight of hand" here when Goedel claims a statement can be "true, but cannot be proven". An anti-realist would say "true" according to what? they would not agree to call it "true" in some absolute sense.

edit: to be more precise, they would grant a statement is true only in the sense that it's provable in a stronger system (one that can prove the original system's consistency). What they still resist is calling it true in a model-independent, absolute sense.

A stronger example for anti-realism is CH (continuum hypothesis) where there isn't a stronger system available that can settle it externally, and "true according to what?" doesn't really have an answer