Lecture 16/65: Facts About Context Free Languages

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  • Опубліковано 3 січ 2025

КОМЕНТАРІ • 14

  • @hhp3
    @hhp3  9 років тому +21

    Thank you very much. What a nice compliment!

    • @villepeltoniemi5004
      @villepeltoniemi5004 9 років тому +1

      +hhp3 Well deserved, too. I've searched through youtube and yours are probably the most comprehensive and clear of all the videos on the topic.

  • @khrotan
    @khrotan 9 років тому +1

    I appreciate all your efforts Mr. Porter. Your videos are brilliant and very clear.

  • @rj-nj3uk
    @rj-nj3uk 5 років тому

    Professor please do a video on Myhill Nerode's theorem. For dfa state minimization and proving a language is regular using it.

  • @spyros07
    @spyros07 9 років тому +5

    Is this another CF grammar for the example?
    S--> 0S1 | 1S0 | ε

    • @FreezeflamesIsrael
      @FreezeflamesIsrael 8 років тому

      Thought of it too,
      I think you should add S ->0|1 in order to allow accept an odd number off characters.

    • @preetomsahaarko8145
      @preetomsahaarko8145 8 років тому

      If you add S-> 0|1, the language accepts 0 and 1, which don't have an equal number of 0's and 1's. On the other hand, S-> 0S1 | 1S0 | ε probably accepts all strings of only even length :) (though it comes to mind in the first thought)

    • @FreezeflamesIsrael
      @FreezeflamesIsrael 8 років тому +1

      Thanks for the explanation :),
      Looking back I'm a bit surprised that I believed odd strings could exist in that language... not sure what I was thinking d:
      (unless you can have half a "1" and half a "0", but I very much doubt it..)

    • @codemixwithmasha3245
      @codemixwithmasha3245 7 років тому

      so this will be allowed as the right answer?

    • @peterkagey
      @peterkagey 7 років тому +2

      Almost! However, you can't make strings like "1001" with that grammar.

  • @mikailkurt5622
    @mikailkurt5622 5 років тому

    Great tutorial! Could someone please explain why this is or isn't correct:
    S --> 11A | 1D1D | A | λ
    A --> 00S | 0C0C | S | λ
    C --> 1S | 1A
    D --> 0A | 0S
    Thanks in advance.

  • @jonathancao1396
    @jonathancao1396 6 років тому +1

    I love you