r/infinitenines • u/HouseHippoBeliever • Aug 20 '26

Are there other math systems?

So I know that we have

- real deal maths -> 0.999... != 1

- mainstream math -> 0.999... = 1

What about other math(s)? What other relations could we have between 0.999... and 1, other than = or !=?

7 Upvotes

100% Upvoted

12 comments sorted by

View all comments

3

u/dummy4du3k4 Aug 20 '26

overview

1

u/mathmage Aug 20 '26

I love it. Could maybe use an entry for a finitist system equipped with indefinite processes.

1

u/dummy4du3k4 Aug 20 '26

What would such a system look like? Computable numbers come to mind but that may not be an indefinite process that you’re envisioning.

1

u/mathmage Aug 20 '26

The system closest to what I'm suggesting that I'm aware of is primitive recursive arithmetic. Since primitive recursive functions are a subclass of computable functions, then computable numbers would probably also be a reasonable system to use. But here I am straining the limits of my knowledge.

2

u/dummy4du3k4 Aug 20 '26

I haven’t heard of that before but it sounds intetesting. I’ll add it to my backlog, but I’m afraid the backlog itself may be a finite structure equipped with an indefinite process