Green's Open Problems #78

### What is the conjecture
https://people.maths.ox.ac.uk/greenbj/papers/open-problems.pdf#problem.78

(Solved) Let $\varepsilon > 0$. Suppose $A \subset \text{SO}(3)$ is open and has sufficiently small (in terms of $\varepsilon$) normalised Haar measure. Is $\mu(A \cdot A) \geq (4 - \varepsilon)\mu(A)$?

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

* ams-22
* ams-28

### 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

Start by reading problem 78 in the linked Green's Open Problems PDF and reviewing how existing conjectures are represented in the formal-conjectures repository. The issue is complete when this SO(3) conjecture is added to the repository in its formalized form.

Written by the indexing model from the issue text.