Quizz 3, question 16

Quizz 3, question 16

by Marc Bernard René Gay-Balmaz -
Number of replies: 5

Hi!

I have a question for that question because, I actually did it right on my paper but named S X1 and X1 S and thus I didn't have the points...
Was there a rule in the lecture about the renaming of the variables when transforming to a CNF I missed?

Thank you in advance for the answer,

Marc Gay-Balmaz

In reply to Marc Bernard René Gay-Balmaz

Re: Quizz 3, question 16

by Mariko Makhmutova -

I did something similar: I made rules S -> X PNP and X -> NP VP, so my answers for questions 16 and 17 are switched (S, X for q16 and S for q17). Is this incorrect?

Thanks in advance,

Mariko

In reply to Mariko Makhmutova

Re: Quizz 3, question 16

by Jean-Cédric Chappelier -

??
I don't understand: with what you say (S -> X PNP and X -> NP VP) I don't see how you can have a S in Q16...
Did I miss something?

In reply to Jean-Cédric Chappelier

Re: Quizz 3, question 16

by Mariko Makhmutova -

Oh my, I redid the whole exercise right now and I certainly do get X, and S,X for the two questions with the same rewriting rules that I used yesterday. Would've been better to do that yesterday, but still good to realize that now. My apologies!

In reply to Marc Bernard René Gay-Balmaz

Re: Quizz 3, question 16

by Jean-Cédric Chappelier -

I don't quite understand: "named S X1 and X1 S",
first of all because you cannot rename S: S is the top-level symbol and you cannot change it.
secondly because looking at your answers you only answered S, no trace of any X1 in your answer.

Maybe could you write your new CNF rules so that I can better understand what you mean?

In reply to Jean-Cédric Chappelier

Re: Quizz 3, question 16

by Marc Bernard René Gay-Balmaz -

Oh, sorry, my bad, I used the other transformation rule (S->A, A->VP PNP) and didn't check the cell that was given (and should have contained my A)