I read about this business in a book on proverbs; but, was unable to find anything about it on SL. Apparently, the line of two space extensions (the author calls a lantern procession) can be cut -- though many think it can't be.
The author states that one would simply "attach and crosscut." I have had little success with this attack and for some reason the author didn't elaborate on the technique.
HolIgor: I don't think that anything good would come from a cut of this position. You need some help from outside if you want to cut. Are the stones in the line placed efficiently? I don't think so. 20 points without the corner. If you can't cut just try to limit it. Keshi works.
In the situation like this you can cut.
you just need the white stone there to cut