Green's Open Problems #89

### What is the conjecture
https://people.maths.ox.ac.uk/greenbj/papers/open-problems.pdf#problem.89

Let $A \subset \mathbb{F}\_2^n$. If $V$ is a subspace of $\mathbb{F}\_2^n$, write $\alpha(V)$ for the density of $A$ on $V$. Is there some $V$ of moderately small codimension on which $\alpha$ is stable in the sense that $|\alpha(V) - \alpha(V')| \leq \epsilon$ whenever $V'$ is a codimension 1 subspace of $V$?

### [AMS categories](https://github.com/google-deepmind/formal-conjectures/labels?q=ams-)

* ams-05
* ams-11

### Choose either option
- [ ] I plan on adding this conjecture to the repository
- [x] This issue is up for grabs: I would like to see this conjecture added by somebody else

Read the linked Green's Open Problems PDF at problem 89 and compare it with the issue's conjecture statement. Determine how this conjecture should be represented in the formal-conjectures repository, then add the formalized statement and verify that the repository accepts it.

Written by the indexing model from the issue text.