[Article] update to Zattera's slot machine

[oshfdk]

But what is the purpose of the grammar?

If we are talking about Mauro grammars, I used them a few times to try understanding the mechanics of the cipher, without much success. I assume that the text is a cipher that uses a small set of glyphs with strong ordering rules to represent arbitrary plaintexts, and the grammar mostly reflects the mechanics of the cipher and not properties of the plaintext. Under this assumption Mauro's grammars are very useful, because they are optimized to minimize the total information content of the grammar and the generated text combined, and I believe they may uncover some essential properties of the cipher by identifying the grammar with the best compression properties.

Under different assumptions, like an exotic language or any other scenario where the grammar is mostly the result of the features of the plaintext and not some mechanical encoding process, I agree that covering only a part of the corpus may be just as useful. Or just as useless.