zagle1772 — 11/13/2025, 5:52:52 PM

I’ve been trying to conceive of an abstract algebra whereïn 9+10=21.

obviously i could just have addition be regular addition plus 2, and then -2 would be the additive identity, and i probably could think of a multiplication that distributes over this addition, but it’s just such a boring addition that i don’t really want to bother

♥ 5 ↩ 0 💬 7 comments

comments

toaks:

alternatively, just change the pronunciation of19 to “twenty-one”

11/13/2025, 7:09:53 PM
geo:

i like this

11/13/2025, 10:38:56 PM
zagle1772:

how the numbers are pronounced ≠ abstract algebra

11/13/2025, 10:55:56 PM
zagle1772:

but i think the latin word for twenty is literally “one down from twenty” not “nine-ten”, so you certainly could call 19 “twenty-one” and 21 “twenty and one”

11/13/2025, 10:57:27 PM
toaks:

Yeah, but I think it's a simpler solution

11/14/2025, 12:10:18 AM
zagle1772:

simple solution is not my goal

11/14/2025, 12:08:45 PM
zagle1772:

i guess (x+2)(y+2)-2 distributes over this addition; it shouldn’t’ve taken me this long to find it, but like i said before, this is a really boring addition, and in fact, this algebra is isomorphic to regular addition and multiplication over the integers.

11/13/2025, 6:31:16 PM