As a part of my assignment at the University I have to go trough Cypher specification. The link on openCypher site is broken. Is this what is published on gihhub current version of openCypher specification? I don't see the version denoted anywhere.
The file name in the grammar link has not been updated to M19, like all the other links.
It should be https://s3.amazonaws.com/artifacts.opencypher.org/M19/grammar-M19.zip.
You should inform the openCypher project so that it can be fixed. I have created a pull request to fix the links: https://github.com/opencypher/website/pull/27