So I saw this question and was curious as to what the Pumping Lemma was (Wikipedia wasn't much help). I understand that its basically a theoretical proof that must be true in order for a language to be in a certain class, but beyond that I don't really get it. Anyone care to try to explain it at a fairly granular level in a way underst...
This isn't a programming question, but I don't know of any good places on the Internets to ask computer science questions. Sorry if this is too off-topic. I'm reviewing some old CS material and I'm stuck on the following: Let L = { x in {a,b}* | x has an equal number of a's and b's} I know this is a context free language because I ca...
Most UNIX regular expressions have, besides the usual *,+,? operators a backslash operator where \1,\2,... match whatever's in the last parentheses, so for example L=(a)b\1* matches the (non regular) language a^n b a^n On one hand, this seems to be pretty powerful since you can create (a*)b\1b\1 to match the language a^n b a^n b a^n whi...
hello i have the following sentence a language L1={a^n * b^n : n>=0} and L2={b^n * a^n : n>=0} are context free languages so they are close a=under the L1L2 so L={a^n * b^2n A^n : n>=0} must be context free too because it is generated by a close property I have to prove if this sentence is true or not so i check the L language and i do...
Hello I am trying to prove that the language L={a^n * b^2n A^n : n>=0} is not context free but i tried the pumping theory but i can not find one state that if i pump then it is out of the language ...
Hey all, I feel like a moron posting such simple questions on here, but the knowledge base of this site is just amazing. Thanks for your understanding. Concerning a question about finding the minimum pumping length (concerning the pumping lemma for regular languages) of a regular expression: Regular Expression R = 1011 (over the alph...