The grammar can be summarized in 11 rules,

The PEG that parses Lojban is the size of an X-Box [...]

I think the operating phrase here is "summarized," it is akin to the way you can write a human-readable book about english grammar even though the only known parser for it is the human brain. [...] My point was that if you wrote a book on Lojban grammar it would have 11 chapters, each meticulously detailing a different category cmavo and their use, how to construct brivla, how to construct lujvo and some other things.

I claim there is no meaningful "summary" of Lojban that constrains itself to eleven "rules", each less than a typical paragraph in length. The reference grammar covers most of the language, taking arguably 18 or 19 chapters to do so. Most of those chapters cover distinct classes of words, to boot.

There is an ancient log that mentions 11 rules in it, but that is just that -- ancient history (circa 1988! A quarter of the LW population wasn't even alive then!). It doesn't even pretend to be a reasonable catalog of the language. Perhaps they've updated since then, but a swift Googling doesn't bring up anything more recent.

In summary, lojban is a hard language mixing the worst of incompressible memorization (e.g., gismu places, lujvo, fu'ivla), archaic logic/maths (e.g., mekso), and just straight-up bad design. I liked it precisely because it was challenging and fun to hack on. At the end of the day, a person wanting to learn a new language is better served by learning a common natlang.