Greibach Normal Form & CFG to GNF Conversion

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  • Опубликовано: 15 июн 2017
  • TOC: Greibach Normal Form & CFG to GNF Conversion
    Topics discussed:
    1) Greibach Normal Form
    2) Steps to convert CFG to GNF
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    Music:
    Axol x Alex Skrindo - You [NCS Release]
    • Axol x Alex Skrindo - ...

Комментарии • 177

  • @Harsh-rm1tp
    @Harsh-rm1tp 4 года назад +901

    only god knows where I'll be using this in my life...

  • @siddharthverma1999
    @siddharthverma1999 3 года назад +81

    For the ones having a doubt on "B -> SB": the example considered is already in the CNF, so there is no need to follow the "STEPS" in order to convert it to the CNF (thereby not following the S' rule). Hope this helps!

    • @anupamladdha4863
      @anupamladdha4863 3 года назад

      Thanks!!

    • @vinayak186f3
      @vinayak186f3 3 года назад +2

      In formal language theory, a context-free grammar, G, is said to be in Chomsky normal form (first described by Noam Chomsky)[1] if all of its production rules are of the form:[citation needed]
      A → BC, orA → a, orS → ε,
      where A, B, and C are nonterminal symbols, the letter a is a terminal symbol (a symbol that represents a constant value), S is the start symbol, and ε denotes the empty string. Also, neither B nor C may be the start symbol, and the third production rule can only appear if ε is in L(G), the language produced by the context-free grammar G.[2]:92-93,106
      Source -wiki

    • @sarthak_saraf
      @sarthak_saraf 2 года назад

      This subject is over for me nowwwww and i am not gonna see this shit again. I m so happy goodbye theory of computation 🗡 u were a bitch

  • @daljeetkaur3002
    @daljeetkaur3002 3 года назад +58

    Oh my god, my teacher makes notes from your videos and teach us by that notes😂😂

  • @giacomodovidio2871
    @giacomodovidio2871 2 года назад +6

    your lessons are powerful!

  • @prathyushsunny
    @prathyushsunny 3 года назад +17

    I recommend you people watch the previous videos on removing unit, null productions along with CFG to CNF conversion. Because steps 1 & 2, which take up majority of the process, aren't being applied to this example(which is a simple one).

  • @voiceofyvr4006
    @voiceofyvr4006 2 года назад +4

    Congratulations for 1.5 million subs 🥳🤩

  • @bhaveshkandpal1706
    @bhaveshkandpal1706 5 лет назад +5

    M fan of the way you teach...thanks a lot..big thumbs up👍

  • @chandreshwarikhanorkar6668
    @chandreshwarikhanorkar6668 5 лет назад

    Excellent Sir.. Thank you so much ...

  • @sankalparora9261
    @sankalparora9261 4 года назад +1

    Thanks. Nicely explained.

  • @khedubaba
    @khedubaba 4 года назад +8

    Those who have doubt of S on RHS thus no CNF.
    So, you check for this(ie: step 1 of converting cfg to cnf as per previous video) when given production is not CNF. That is we begin with the procedure if given production is not in CNF form. But here given production is already CNF. Thus we don't follow those steps and it doesn't matter if S is on right side because its already in CNF form.

  • @siddharth.chandani
    @siddharth.chandani Год назад

    Here 5:00 you solve my doubt.. Thanks sir

  • @saicharan823
    @saicharan823 5 лет назад

    Great lecture . Impressed with it !!

  • @kgCode658
    @kgCode658 5 лет назад +3

    Nice video sir... completely able to understand the concept...☺️☺️

  • @friendlyneighbourhood930
    @friendlyneighbourhood930 4 года назад

    Thank you, Sir.😊😇

  • @MohammadHassan-vd2zo
    @MohammadHassan-vd2zo 13 дней назад

    good teaching

  • @vinayaksharma-ys3ip
    @vinayaksharma-ys3ip 3 года назад

    Thank You So much sir👍👍👍

  • @Nomnomnom165
    @Nomnomnom165 Год назад +12

    The steps are clear to me, thanks for the video. But i have one doubt. If it is already in Chomsky Normal Form, doesn't that mean that unit and null productions are already removed? And if so, is it fine to just check if it's in Chomsky Normal Form directly?
    Please correct me if I made some error

  • @Ansari_Zubair
    @Ansari_Zubair 5 лет назад +12

    Why should do Step 1,when we know that in CNF these Step Have to do.We should do directly step 2.

  • @KamalSingh-nv7nh
    @KamalSingh-nv7nh 3 года назад

    Thank you sir👍

  • @rishikrishsharma2654
    @rishikrishsharma2654 6 лет назад +34

    In the CNF lecture you said that Start Symbol S must not be on Right hand side and inn this lecture S is in RHS than you also considered it as CNF

    • @nikhilsharma8350
      @nikhilsharma8350 4 года назад +2

      Yes it's right can can you explain me why did this happen in this example.please response me if you know

    • @yashrajsingh8700
      @yashrajsingh8700 4 года назад +18

      @@nikhilsharma8350 If you see in previous example it was A->S and in this it is B->SB. Hence alone if S is found then we have to change.

    • @udiptadeka562
      @udiptadeka562 3 года назад +2

      I think there is a mistake as discussed in CNF S->ASB and A->S due to which we took a new production here too there is a state B->SB

  • @shashirekha3021
    @shashirekha3021 4 года назад

    Amazing videos

  • @mohamedkanu66
    @mohamedkanu66 4 года назад +2

    MAny thanks for the good job. Please can you do a video on conversion of
    regular expression to context free grammar. Please help us as urgent as possible

  • @imranshaik5325
    @imranshaik5325 2 года назад +1

    thanks

  • @adarshpawar
    @adarshpawar 6 лет назад +20

    Why didn't we convert S'-> S? Because according to be in Chomsky Normal Form when S is in left side so we take S'.

    • @diodesu
      @diodesu 2 года назад +1

      Yeah I agree. The expression was still not fully converted into a CNF.

    • @vampyrkiller
      @vampyrkiller Год назад

      Right not left bro

  • @iyadhabdessalem3496
    @iyadhabdessalem3496 2 года назад

    thank you

  • @user-sp8dl8ll8b
    @user-sp8dl8ll8b 2 месяца назад +4

    Aren't we going to add S'-> S???

  • @gagaadadasdadadas
    @gagaadadasdadadas 5 лет назад

    thx man ! nice explaind !

  • @dhanushsivajaya1356
    @dhanushsivajaya1356 3 года назад

    Thankyou sir

  • @vardaanbajaj3181
    @vardaanbajaj3181 4 года назад +2

    If i have a production of the form: A1 -> b A4 A3 A2 (A1, A2, A3, A4 are Non-terminals and b is a terminal), will this production be in GNF?

  • @dennisthomas971
    @dennisthomas971 3 года назад

    Thank you❤🙏

  • @Rohit-qp1ye
    @Rohit-qp1ye 5 лет назад

    Good work sir keep going

  • @tahreenshaik277
    @tahreenshaik277 7 лет назад +1

    please upload videos on pda and turing machine .i have my exam on 20 june

  • @AhamedKabeer-wn1jb
    @AhamedKabeer-wn1jb 3 года назад

    Thank you ..

  • @gopichandh5239
    @gopichandh5239 5 лет назад +3

    not in CNF form as S is in the right hand side

  • @omerihtizaz9043
    @omerihtizaz9043 3 года назад +1

    You said that when i -> j , i < j not i >= j
    however when we see A4 -> b | b A3 A4 | A4 A4 A4
    you say that the part b A3 A4 is in normal form however here i == j

    • @kriskhandelwal6967
      @kriskhandelwal6967 3 года назад +3

      it started with a non terminal symbol that's why it was accepted
      if it would have been A3bA4 then we would have to replace the A3
      but since it started with b it was accepted

    • @clipfams8887
      @clipfams8887 3 года назад

      @@kriskhandelwal6967 thanks bouiiiiii

    • @clipfams8887
      @clipfams8887 3 года назад

      @@kriskhandelwal6967 thanks

  • @jatinbansal4759
    @jatinbansal4759 4 года назад +1

    it will be really helpful if you provide the image of the things you tought over here

    • @NSTuts
      @NSTuts 3 года назад +1

      screen shot lele na pagal

  • @webtube4131
    @webtube4131 4 года назад

    S occurred on the right side in the given example so it is not in CNF but how did you proceed further without converting it to CNF (please help I have exam tomorrow )

  • @AadityaChouhan
    @AadityaChouhan 6 месяцев назад +1

    But, At 3:54 according to CNF the starting symbol shouldn't be on RHS of any production rule...😢

  • @01Nullvoid
    @01Nullvoid Год назад +1

    Excuse me sir! 3:50
    here there S on right side of production. And how it is already in CNF??

  • @rachitchhabra9578
    @rachitchhabra9578 6 лет назад +39

    B-->SB. Here it is not in Chomsky Normal Form since S is on the right side. Please explain!!?

    • @anuragroy11
      @anuragroy11 6 лет назад +1

      Same question!

    • @kunaldeshpande6487
      @kunaldeshpande6487 6 лет назад +4

      rachit chhabra no buddy S is right side still it is non terminal because it's a starring point....... Generally it's non terminal

    • @ChristianBurnsShafer
      @ChristianBurnsShafer 6 лет назад +6

      Yes, we would have to add the production S' -> S. Small oversight.

    • @ritraina
      @ritraina 6 лет назад +2

      u r asking a right question but d thing after removing unit production s'-s the s' will be extended with what s has now

    • @ActiveMentorAI
      @ActiveMentorAI 6 лет назад

      exactly

  • @nabhavlogs371
    @nabhavlogs371 5 лет назад +10

    A4-->b A3 A4? is this possible?

  • @kerteske3811
    @kerteske3811 3 года назад

    I was searching for GNF - Polo G

  • @usamafiaz6964
    @usamafiaz6964 2 года назад

    Is there any Solution Manual for Automata By cohen and denial ?

  • @gouravchatterjee7052
    @gouravchatterjee7052 6 лет назад +4

    it can be done in a simpler way also

  • @shubhammishra4122
    @shubhammishra4122 7 лет назад +1

    Sir i have my examss from 6th of july . It would be very helpful if you put now.

  • @HighbrowDirector
    @HighbrowDirector 3 года назад +3

    I think you forgot to change 'A3' to 'a'.

    • @sparkplug8763
      @sparkplug8763 3 года назад +2

      no, that breaks the definition of GNF which is 'one terminal followed by n non-terminals'
      it's already in GNF so I guess the i < j part can be ignored.

  • @RA-CSEA-eh3es
    @RA-CSEA-eh3es 3 года назад

    In step 4 what if it had....(A4->A4|A3)?

  • @MAX-rb2vh
    @MAX-rb2vh 2 года назад

    Why did we write A4 twice?

  • @abanoubbenyamin1729
    @abanoubbenyamin1729 Год назад

    Doesn't BB in S makes it not in CNF because BB is repeated

  • @user-ox8qd3wv4d
    @user-ox8qd3wv4d 11 месяцев назад

    Sir urgent doubt hai........
    Diff. Method sai different answer aa sakta hai na?
    Bs condition satisfy Krna chaiye...
    Sir vo dusra method jismai A1,A2,A3 assume krte usse different aaraha

  • @merida3975
    @merida3975 2 года назад

    still have many doubts

  • @HighbrowDirector
    @HighbrowDirector 3 года назад +1

    Since we are already removing Unit Productions and Null Productions in CNF, Why do we need step 1 here?

    • @vaishnaviv2169
      @vaishnaviv2169 3 года назад

      The step which he said in the first, is for the conversion from CFG to GNF and not CNF to GNF.

    • @HighbrowDirector
      @HighbrowDirector 3 года назад +1

      @@vaishnaviv2169 If its already a CNF there will be no Null productions and Unit productions.

    • @vaishnaviv2169
      @vaishnaviv2169 3 года назад

      @@HighbrowDirector yeah... So, did he remove some unit or null values bymistake?
      Or is there any mistake in that video?

    • @HighbrowDirector
      @HighbrowDirector 3 года назад +1

      @@vaishnaviv2169 Actually no mistake 1 step was redundant

  • @GustavoFringe-dv2yg
    @GustavoFringe-dv2yg Год назад +9

    tomorrow is TOC exam,,, Wish me luck guys😥

  • @junaidshaikh3597
    @junaidshaikh3597 6 лет назад

    This example is wrongly solve d

  • @shubhammishra4122
    @shubhammishra4122 7 лет назад

    Sir i need to learn whole turning machine . How much to pay you to get it?

  • @vikrampareek8713
    @vikrampareek8713 6 лет назад +1

    wrong!! As B->SB has S on right side. it is not in CNF!! Please do convert it

  • @amrabuodeh
    @amrabuodeh 4 года назад

    replace the valoo

  • @E2_1B
    @E2_1B 8 месяцев назад

    Here we go generational pain.

  • @ozgunozerk334
    @ozgunozerk334 4 года назад +1

    its not gridback, its gribah (i pronounced like "i")
    :))))))))

    • @adilbimzagh5453
      @adilbimzagh5453 4 года назад

      it's not gribah eather ! the therm "ch" has its own prononciation !

  • @smrpkrl
    @smrpkrl 5 месяцев назад

    3:04

  • @RohitArtCraft
    @RohitArtCraft Год назад +1

    Sir you are great but your voice is not perfect

  • @Sortedarray32
    @Sortedarray32 2 года назад

    Dukh dard peeda kasta

  • @eeshankhan4607
    @eeshankhan4607 5 лет назад +1

    A of 1 😂😂😂

  • @saurabhjondhale
    @saurabhjondhale 4 года назад +2

    it should be A4--> b | A2 A3 A4 | A4 A4 not A4--> b | A2 A3 A4 | A4 A4 A4

  • @kakashi7943
    @kakashi7943 Год назад +2

    Wrong solution

    • @user-sp8dl8ll8b
      @user-sp8dl8ll8b 2 месяца назад

      What's the wrong solution?
      May I know??

  • @ArifKhan-kp8zs
    @ArifKhan-kp8zs 7 лет назад +8

    ab exam ho gaya ab kya dal rahe hoo. 😨😨ye questions exam me v aya tha

  • @RashmiSingh-rl5ge
    @RashmiSingh-rl5ge 5 лет назад +4

    Could you go any slower😒

    • @ManishSharma-lm3wg
      @ManishSharma-lm3wg 5 лет назад +3

      Sorry to interrupt but he is already slow,
      Or watch at *.75 speed 😂

    • @RashmiSingh-rl5ge
      @RashmiSingh-rl5ge 5 лет назад

      Manish Sharma Fitness I was being sarcastic dude

    • @bharanivishwamitra
      @bharanivishwamitra 4 года назад +2

      @@ManishSharma-lm3wg Can you be any dumber, oof!

  • @Ali1u585
    @Ali1u585 3 месяца назад +3

    I beleive that this subject is the most useless subject in the world

  • @_Yank_
    @_Yank_ 6 лет назад

    bcoz of one small mistake u done in the whole que is gone wrong and my last 2h before the exam day gone to hell
    can u pls post another video in which u didn't do such type of silly mistake of S on the right side of CNF that u didn't recheck whether what u r teaching is right or not

  • @mohamedkanu66
    @mohamedkanu66 4 года назад

    MAny thanks for the good job. Please can you do a video on conversion of
    regular expression to context free grammar. Please help us as urgent as possible