In "52.2.2.1. Multiple Statements in a Simple Query" there is supposed to be a typo in the last example. I cannot find it, even having diffed the two examples. Hopefully I am not crazy.. All the best, Leo!
This has already been fixed at 8a47b775 and will show up in the next minor release of version 12. The "devel" version (and prior versions as the original "fix" wasn't back-patched) of the documentation on the website shows what it will look like.