Skip to main content
7 events
when toggle format what by license comment
Sep 22, 2018 at 13:02 comment added Paolo Lipparini You're right, I have taken things the other way round (it sometimes happens ;). Yes, additive inverses do work, and the whole stuff becomes a Ring, I have edited the answer. I suggest you to write a paper about the subject!
Sep 22, 2018 at 12:56 history edited Paolo Lipparini CC BY-SA 4.0
added further considerations: the last possibility E seems viable
Sep 19, 2018 at 11:35 history edited Paolo Lipparini CC BY-SA 4.0
clarifications
Sep 17, 2018 at 22:01 comment added Gro-Tsen I want $≜$ to imply $≐$ (i.e., the sought-after equivalence relation $≜$ is stronger, i.e., has smaller classes, and I call this "finer", than Conway's $≐$). So in fact I want (E) but apparently what you call "coarser" is what I (and Wikipedia) call "finer". Sorry about the confusion. I believe additive inverses should still work if I define $G≜G'$ as something like "$G⊗H≐G'⊗H$ for all $H$", which is what I proposed.
Sep 17, 2018 at 20:28 comment added Paolo Lipparini I have understood your question in the sense that $\triangleq$ should be such that if $G \doteq H$, then $G \triangleq H$. So if $1/2 + 1/2 \doteq 1$, then $1/2 + 1/2 \triangleq 1$. Of course, we can consider instead a relation coarser than $\doteq $, as I mentioned in (E), but then it is hard to get a group, that is, to have additive inverses.
Sep 16, 2018 at 11:03 comment added Gro-Tsen Of course, there is a game $x$ that corresponds to (say) the Hackenbush realization of Conway's $½$, which satisfies $x+x≐1$, but it will not satisfy $x+x≜1$. So my question is about renouncing $½$ if you want, but not renouncing it in the sense that it ceases to be a game, but that it does not have a representative satisfying $x+x≜1$.
Sep 15, 2018 at 20:05 history answered Paolo Lipparini CC BY-SA 4.0