In the seventh century C.
E.
The sixth treatise is very difficult to understand, to the point that even well-educated Tibetans often have not studied and learned.
This book presents two of the most popular Tibetan texts that explain the sixth one, called The Application of Gender Signs. the Tibetan man Thumi Sambhota wrote eight treatises that defined Tibetan grammar and lettering, but only two of them still exist, the others have been lost about two centuries after they were composed.
In the seventh century C.
E