sum cu pa dang rtags kyi 'jug pa by thon mi Sambhota; grammar and spelling. Syn {sum cu pa dang rtags 'jug pa}; "Thirty and Signs". The popular abbreviation of the "Root Grammar in Thirty Verses" {lung ston pa rtsa ba sum cu pa} and the "Grammar, the Guide to Signs" {lung du ston pa rtag gi 'jug pa}. See those entries. These two are often put together like this as one word because they are the only two surviving treatises of the original eight treatises which defined Tibetan grammar. By saying {sum rtags} one effectively says "Tibetan grammar". [TDuff]