barnaby wrote on 05/02/12 at 06:56:30:

Strange, so in this supposed classification it is only QGD vs QGA? Kind of like Open vs Closed Spanish, even though the Open Spanish is a much smaller variation compared to the whole opening. But what makes you think that Schandorff treats the Slav complex in this way? The only thing he does is have a small section with the title QGD in the semi-slav chapter, but that is because Black can transpose back to some passive non-exchange QGD lines from the 5 Bg5 Semi-Slav.

Anyway, there is no easy answer to the question 'what is the semi-slav?' - there are lines which are clearly semi-slav, such as the Moscow/Anti-Moscow, Meran/Anti-Meran, but the Triangle for example? Who knows? The title of the Scherbakov book would suggest he thinks the Triangle is a kind of Semi-Slav ("... and other semi-slav lines") but it is not clear.