"Theory of Computation"; Portland State University: Prof. Harry Porter; www.cs.pdx/~harry
Пікірлер: 53
@amichael96707 жыл бұрын
Let's all thank God for this human being :-)
@blabarsris60123 жыл бұрын
@Brentley Jaxtyn wtf
@RED-pi9wo8 жыл бұрын
Thanks man! I got an exam in like 2 hours. Just learned it all from scratch.
@computerscientist59538 жыл бұрын
lol...
@mudsky8 жыл бұрын
was feeling crap about starting the night before, but this gave me hope. lmao
@Dr1nc7 жыл бұрын
i'm in the exact same spot right now lol
@doguseyidoglu59376 жыл бұрын
my exam will start in two hours lol
@osama0020096 жыл бұрын
The Same with me Lol
@cesaredecal22305 жыл бұрын
These videos are pure gold, I feel I understand everything with your teaching style. I appreciate how concise and clear these videos are. Thanks!
@HollyFRyan6 жыл бұрын
You're so goals. I'm in love. You turn logic into lovemaking with your beautiful videos. Thank you Harry Porter
@hhp36 жыл бұрын
Holly Whimsy Thanks for your nice compliment, Holly.
@plekkchand3 жыл бұрын
Hmm. You might be getting a little carried away here....
@amirkamalian80456 жыл бұрын
*2018 poor computer science student here and I have no fucking Idea why should I know these things But thank god I found you Thank you*
@Braden_Buchanan6 жыл бұрын
this comment is me rn lmao
@spyros079 жыл бұрын
Thank you so much Professor.
@mandy13397 жыл бұрын
reupload videos with higher resulution please. These are gold.
@kenudice98412 жыл бұрын
Review 12:30 for understanding grammar and language definitions.
@james_015 жыл бұрын
Thank you for explaining things so clearly.
@corbinmckeeth21246 жыл бұрын
you're a wizard harry!
@pablobiedma4 жыл бұрын
never heard that joke before
@Liaomiao4 жыл бұрын
What this made earlier? Not quite as clear as the FSM segments, still good though.
@ydanneg Жыл бұрын
Starting from this video this course became really complicated to understand. What happened?
@BrettClimb7 жыл бұрын
If you had the expression A = B + C * D, and you did a LMD using an ambiguous grammar, couldn't that potentially add B + C before multiplying by D, and if you did a RMD, couldn't it multiply C * D before adding B? In other words, for an ambiguous CFG, wouldn't the LMD and RMD produce different parse trees, and not be abstracted to the same parse tree?
@DeveshBeri8 жыл бұрын
In the first example, after 'a + F', why didn't we made it 'a + a' instead of making it 'a + (E)'??
@aminazmus8 жыл бұрын
+Devesh Beri Do you got the answer?
@mudsky8 жыл бұрын
been bothering me too. any answers?
@LeTheory7 жыл бұрын
Would a + a be accepted instead of a + (a x a)?
@dr13035 жыл бұрын
"a + (E)" and "a + a" are both described by the grammar, so both are correct. The purpose of a grammar is (usually) not to generate expressions, but to check if they are valid. In this case the question would be "Is 'a + (a * a)' valid within this grammar?", and the answer is "Yes, because we can apply the rules until we arrive at that string of characters."
@onursimsek60945 жыл бұрын
@@dr1303 Is 'a' valid within this grammar ?
@eljeanxp8 жыл бұрын
How do you know when to stop expanding?
@kenanofify7 жыл бұрын
You stop expanding when there is no more non-terminals (when all of the symbols are terminals). At this point, there is no way to expand anymore. Consider "a + (a x a)", 'a' is a terminal symbol and there is no way to convert it to any other symbol, and also ('+', 'x', '(', ')') are all terminals.
@selamikadoglu74514 жыл бұрын
Tomorrow we have an exam ! And this video gave me hope too much...Appreciate thanks thanks muah muah i love yaaaaaaaaaaaaaaaaaa...
@agakov13 жыл бұрын
Thank you!
@ZawirAmin9 жыл бұрын
Definition: 12:33
@navneetrks9 жыл бұрын
Thank you! Sir !
@21stcenturygurl4 жыл бұрын
Thank you for this sensational video!
@ghty1028 жыл бұрын
What I can't seem to figure out is, when doing a left most derivation; does this assume we use the left-most rule in the CFG rules as well? Like what if your grammar is: S->a|B B->Bb|b is the left-most derivation just S=>a? because a is the left-most rule in the definition S->a|B? How do we determine rule to use in these types of situations?
@iali019877 жыл бұрын
No and this is because A or B is the same as B or A. So S -> a|b is the same as S -> b|a You don't apply the left mot derivation when choosing a rule.
@dr13035 жыл бұрын
Nope. Left most derivation is the idea of expanding the left-most token in your input. With your example grammar, and the input of "SB": SB => aB => aBb => abb Thus "abb" is valid grammar. If we only chose the left rule, we would arrive at: SB => aB => aBb => aBbb => aBbbb => aBbbbb => ... This tells us that abbbbbbb... is also valid within this grammar. This is however an infinite string, which is rather impractical, so at some point it must NOT follow the left most rule of B -> Bb, but rather the right rule of B -> b. This will give the string a finite length.
@onursimsek60945 жыл бұрын
Is the following derivation also true : E -> T -> F -> a
@ridwa5 жыл бұрын
yes, it is
@ManoToor7 жыл бұрын
Thank you for these videos, they are very helpful
@GoodStageProduction02 жыл бұрын
UGA 2021 boi!!!!
@bilal.ashraf9 жыл бұрын
Great stuff..!
@Marox007-m3i6 жыл бұрын
thank you
@omart94113 жыл бұрын
this was uploaded in 2015 why the potato quality?
@realAgitated4 жыл бұрын
I don’t get it I absolutely hate this, because I don’t know why I don’t understand any of it.