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Problem Detail: I wonder whether the following language is a context free language: $$A = {w in {a,b,c}^* mid #_a(w) + 2#_b(w) = 3#c(w)}$$ where $#_x(w)$ is the number of occurrences of $x$ in $w$. I can’t find any word that Read More …

Problem Detail: We’re in a shared memory concurrency model where all reads and writes to integer variables are atomic. do: $S_1$ in parallel with: $S_2$   means to execute $S_1$ and $S_2$ in separate threads, concurrently. atomically($E$)   means to evaluate $E$ Read More …

Problem Detail: what is the complexity of below relation $ T(n) = 2*T(sqrt n) + log n$ and $T(2) = 1$ Is it $Theta (log n * log log n)$ ? Asked By : panthera onca Answered By : Ken P Yes, the Read More …

Problem Detail: Wiki (http://en.wikipedia.org/wiki/Sharp-P) says ‘In computational complexity theory, the complexity class #P (pronounced “number P” or, sometimes “sharp P” or “hash P”) is the set of the counting problems associated with the decision problems in the set NP’. Is there Read More …

Problem Detail: Some sets of ordered binary trees can be represented as a CFG with rules of the form A -> aBC A -> b Where A,B,C are nonterminals and a and b are terminals representing internal nodes and leaf nodes Read More …

Problem Detail: My setup is something like this: I have a sequence of sets of integers $C_i (1leq ileq n)$, with $|C_i|$ relatively small – on the order of four or five items for all $i$. I want to choose a Read More …

Problem Detail: It is said that “The Turing machine is not intended as practical computing technology, but rather as a hypothetical device representing a computing machine. Turing machines help computer scientists understand the limits of mechanical computation.” [Wikipedia] So on which Read More …

Problem Detail: Why is $A(L) = {x in L mid x = x^R }$ context-free if $L$ is a regular language? Trying to understand the approach to determining whether a regular language is context-free. Asked By : Iancovici Answered By : Ran G. Read More …

Problem Detail: PIC16F887 Block Diagram According to the block diagram above, since we already have Program Memory, which may be used to store our program, why should we still need EEPROM? What is it for? Asked By : AlbertK Answered By : frafl Read More …

Problem Detail: I’m trying to understand the difference between LTL and CTL. In particular, i’m trying to understand when a model (a transition system eg. Kripke structure) satisfy a formula. This is my point of view: a model satisfy an LTL Read More …