# LMD Async Tutoring **URL:** https://discuss.criticalfallibilism.com/t/lmd-async-tutoring/1933 **Category:** Tutoring **Created:** [April 23, 2024, 12:05am UTC](https://discuss.criticalfallibilism.com/t/lmd-async-tutoring/1933 "2024-04-23T00:05:39Z") **Posts on this page:** 1 **Showing post:** 437
### Author: ![LMD](https://discuss.criticalfallibilism.com/user_avatar/discuss.criticalfallibilism.com/lmd/32/3213_2.png) [@LMD](https://discuss.criticalfallibilism.com/u/LMD) #### Post date: [July 24, 2024, 2:27am UTC](https://discuss.criticalfallibilism.com/t/lmd-async-tutoring/1933/437 "2024-07-24T02:27:55Z")
> [@Eternity Async Tutoring](https://discuss.criticalfallibilism.com/t/eternity-async-tutoring/1932/433): > > You can look for another solution for or(x,y) now which uses remainder. This is my working. In it I happen upon a remainder solution to xor. I’m still stuck on a remainder solution to or though. 1 % 5 = 1 2 % 5 = 2 3 % 5 = 3 4 % 5 = 4 5 % 5 = 0 I want to map: 0 → 0 1 → 1 2 → 1 5 % 1 = 0 5 % 2 = 1 5 % 3 = 2 5 % 4 = 1 5 % 6 = 5 5 % 7 = 5 5 % 8 = 5 … 6 % 1 = 0 6 % 2 = 0 6 % 3 = 0 6 % 4 = 2 6 % 5 = 1 6 % 6 = 0 6 % 7 = 6 … 3 % 1 = 0 3 % 2 = 1 3 % 3 = 0 3 % 4 = 3 … So a first number mod a second and larger number outputs the first number 5 % 1 = 0 6 % 2 = 0 7 % 3 = 1 8 % 4 = 0 9 % 5 = 4 10 % 6 = 4 11 % 8 = 3 3 % 1 = 0 4 % 1 = 0 0 % 2 = 0 1 % 2 = 1 2 % 2 = 0 3 % 2 = 1 4 % 2 = 0 5 % 2 = 1 6 % 2 = 0 7 % 2 = 1 8 % 2 = 0 9 % 2 = 1 Okay so using ‘% 2’ can check if something is even or odd. That means you could use it for xor. > **xor(x, y) = (x + y) % 2** Okay, so I am conceptually trying to do the same thing as with division. Mapping 0 to 0, and 1 and 2 to 1. The hint was to try n/10. That made me see that anything under 10 output 0 and anything above output 1. So I want a way that I can use remainder do the same thing. Can I use remainder to check primes? I know that 1 and 2 are both primes. if there was a prime check function called ‘prime’ that output true when prime, i could do: 0 prime 0 1 prime 1 2 prime 1 When is something a prime? When it has no factors except 1 and itself. I think I would maybe need to recursively check that each number below the input wasn’t a factor though. What other things maps 0, 1, 2 to 0, 1, 1? A remainder function subtracts the second number from the first number until it cant and then returns the remainder. If i could multiply 0, 1, 2 by something, that would spread them out across the number line, keeping 0 at 0. But they’re then all scaled by the same amount. Hmm. Stuck for now. --- _[View the full topic](https://discuss.criticalfallibilism.com/t/lmd-async-tutoring/1933)._