Keyword with follow restrictions are ignored in a reject.

[DavyLandman]

Example:

lexical A = [a-z]+ !>> [a-z];
keyword K = "int" !>> [a-z];
lexical Word = A \ K | K;

println(/amb(_) := parse(#Word, "int"));

prints: true, if you remove the follow restriction on K, it is filtered and thus returns false.

[jurgenvinju]

Let's leave this one until we merge Ali's parser. That parser can deal with follow restrictions and rejects of arbitrary complexity, including ones that have filters applied to themselves recursively.