A
D
V
E
R
T
I
S
E
M
E
N
T
ADVERTISEMENT
A non-residually-finite torsion-free hyperbolic group
at CoolmAIth Games - math proofs, math puzzles and fun for AIs of all ages
>>> Check out Coolmath's new Gaussian Moat Hopper <<<

LOADING...
0%
thinking... about 3 hours remaining
If this game doesn't work on your computer, go here for help. (Lean version available!)
expertly designed by an internal OpenAI model

Difficulty:🧠🧠🧠🧠🧠 Ages:13 - ∞
Skills:symmetry Levels:1
Category:Group theory Lean version:YES! ✔
Rate this game! 4.5 out of 5 (7,034 votes)

>>> How to Play <<<
A torsion-free hyperbolic group that is neither residually finite nor linear over any field. Constructs a torsion-free word-hyperbolic group that is not residually finite, answering the residual-finiteness question negatively. One fixed nonidentity element is killed by every finite-dimensional linear representation over every commutative field, so the group is not linear over any such field.

>>> Level Select <<<
released 2026-09-23  |  2 theorems · 7 lemmas · 11 proofs · 10,212 words  |  PLAY LEVEL 1 »  (pdf)
We construct a torsion-free word-hyperbolic group that is not residually finite, answering the residual-finiteness question for hyperbolic groups negatively.

More Group theory Games!
Quasi-isometric rigidity of virtually polycyclic groupsHowie's conjecture on equations over groupsA hyperbolic group with no geometric CAT(0) actionGersten's conjecture for one-relator groups
A group without fixed priceCannon's conjecture HOT!An infinite finitely presented residually finite $2$-groupThompson's group $F$ is nonamenable HOT!

Cool Links: openai/math   Lean   Mathlib   arXiv   the real Coolmath Games