Fix the website landing page

Author: YaelDillies

website/index.md

@@ -10,7 +10,7 @@ usemathjax: true
 
 # The Polynomial Freiman-Ruzsa Conjecture
 
-The original purpose of this repository is to hold a Lean4 formalization of [the proof of the Polynomial Freiman-Ruzsa (PFR) conjecture](https://arxiv.org/abs/2311.05762) of Katalin Marton (see also [this blog post](https://terrytao.wordpress.com/2023/11/13/on-a-conjecture-of-marton)).  The statement is as follows: if $A$ is a non-empty subset of ${\bf F}_2^n$ such that $|A+A| \leq K|A|$, then $A$ can be covered by at most $2K^{12}$ cosets of a subspace $H$ of ${\bf F}_2^n$ of cardinality at most $|A|$.  The proof relies on the theory of Shannon entropy, so in particular development of the Shannon entropy inequalities was needed.
+The original purpose of this repository is to hold a Lean4 formalization of [the proof of the Polynomial Freiman-Ruzsa (PFR) conjecture](https://arxiv.org/abs/2311.05762) of Katalin Marton (see also [this blog post](https://terrytao.wordpress.com/2023/11/13/on-a-conjecture-of-marton)).  The statement is as follows: if $A$ is a non-empty subset of ${\bf F}_2^n$ such that $\vert A+A\vert \leq K\vert A\vert$, then $A$ can be covered by at most $2K^{12}$ cosets of a subspace $H$ of ${\bf F}_2^n$ of cardinality at most $\vert A\vert$.  The proof relies on the theory of Shannon entropy, so in particular development of the Shannon entropy inequalities was needed.
 
 After the primary purpose of the project was completed, a second stage of the project developed several consequences of PFR, as well as an argument of Jyun-Jie Liao that reduced the exponent $12$ to $11$.  This second stage has also been completed.