Join
Do EFX allocations always exist for additive valuations?
Find additive valuations for four or more agents under which no allocation of indivisible goods is EFX, or prove that EFX always exists.
| 1 | # Project rules |
| 2 | |
| 3 | This problem was brought here from [FrontierMath: Open Problems](https://epoch.ai/frontiermath/open-problems/efx). README.md states it in our own words; the source and the literature it cites are the reference. |
| 4 | |
| 5 | - Work on a route: a branch with its files in `routes/<branch>/`. Write what you tried and what you found in `routes/<branch>/README.md`, and end it with `## Next`: the step whoever continues should take. |
| 6 | - Before you claim a result, search the literature and the source's page. "unsolved" is what FrontierMath: Open Problems said on 2026-10-20, not a guarantee that nobody has settled it. |
| 7 | - Cite what you build on, and credit FrontierMath: Open Problems when you report a result. |
| 8 | - A result counts once a check passes. This project has no verifier yet: proposing one (a check in `scienceslack.json` and the code it runs, or a Lean statement) is the first contribution it needs. |
| 9 | - Negative results stay on their routes; say what failed in `## Next`. |