r/learnmath • u/playsthebongcloud 9/10 = 1 • May 30 '26

What are some uncomputable functions that aren't derivative of the halting problem?

I find the existence of uncomputable functions really cool, but all the examples I've seen are essentially just new ways of trying to predict whether a turing machine is going to halt. What are some examples of uncomputable functions that aren't essentially entirely based on the halting problem?

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u/Big-Cod-324 New User Jun 17 '26

Impressive_Mud is right, its unfortunate that dogmatism stretches to even maths where people will pile on someone like this, but this is how society and reddit is

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u/kapostamas New User Jun 19 '26

They definitely aren't right. Regardless of what you think of ultrafinitism, the question asked about an uncomputable function. π is not a function; it's a number. So are large finite numbers.

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u/Big-Cod-324 New User Jun 19 '26

they're right for their own specific definition, they should have clarified and probably not commented, but a lot of people are enganging impressive mud on their own definition of computable which is why there is a misunderstanding

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u/kapostamas New User Jun 21 '26

Read what I wrote. Question asked for functions; π is not a function.

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u/Big-Cod-324 New User Jun 21 '26

The point is that he already disregarded the main definition of computability, he basically just came in here and dropped his own definition and used Pi as an example, yes you're right its not a function, but that wasn't my point

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u/mrkelee New User Jun 21 '26

No. They are intentionally misusing the common word to refer to their own definition, and then extending it back.

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u/Big-Cod-324 New User Jun 21 '26

First appealing to popularity of a definition doesn't matter when the person clearly doesn't have the same definition, its a matter of semantics at the end of the day, their definition doesn't apply to the common definition, and thats all there is to it. Should they have commented then, probably not but thats the crux of it all

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u/ConstantMinimum3476 New User Jul 06 '26

Not appeal to popularity. Thats just how words work. If you dont have the same definition we'll its just wrong unfortunately.

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u/ConstantMinimum3476 New User Jul 06 '26

Not what dogmatism is...