Update book/src/see_also.md

Co-authored-by: Rémy Rakic <[email protected]>

Author: lengyijun

book/src/see_also.md

@@ -7,7 +7,7 @@ There have been a number of blog posts related to Polonius as it evolves:
 - [Polonius and the case of the hereditary harrop predicate](https://smallcultfollowing.com/babysteps/blog/2019/01/21/hereditary-harrop-region-constraints/)
 - ... TODO add the rest ...
 
-[polonius-proof](https://github.com/lengyijun/polonius-proof/) uses theorem prover to prove that `naive` and `datafrog-opt` generate same error.
+[polonius-proof](https://github.com/lengyijun/polonius-proof/) uses a theorem prover to prove that the `naive` and `datafrog-opt` variants generate the same errors.
 
 The academic work "Oxide" is partially inspired by Polonius: