For those of you who did not attend Nov. 13th lesson (or those who missed the point): slides 41/47 to 45/47 of "Parsing and formal grammars" lecture (started Nov. 06th) were NOT done this year and are thus NOT expected to be known this year. So don't bother any like notation this year; simply replace it by "some non-terminal".
Especially in slide 22/29 of today's lecture ("stochastic parsing"), understand , as non-terminals on the picture and forget about (= remove) the sentence that talks about .
I also take the opportunity to mention again that Earley parsing is no longer in the scope of the course (but was last year). So don't worry about that either.