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Problem Detail: What is the meaning of the double, down facing arrow $Downarrow$ in the context of operational semantics? Here’s the example formula that uses it: $$frac{s_0 vdash M_1 Downarrow P_1, s_1 ; … ; s_{n-1} vdash M_n Downarrow P_n, s_n}{s_0 Read More …

Problem Detail: Which machine learning algorithms (besides SVM’s) use the principle of structural risk minimization? Asked By : Classifire Answered By : jmad The structural risk minimization principle is a principle that is at least partly ‘used’ in all machine learning methods, since Read More …

Problem Detail: Let a input string be given as $w_1w_2…w_n$. Then if a NFA is currently in state $r$ ( and has read the input upto alphabet $w_i$ ) then before reading the next input symbol the NFA splits into two Read More …

Problem Detail: Given a program consisting of variables and instructions which modify these variables, and a synchronization primitive (a monitor, mutex, java’s synchronized or C#’s lock), is it possible to prove that such a program is thread safe? Is there even Read More …

Problem Detail: I am working on my thesis which involves using ant based techniques for graph clustering. I am testing the algorithm currently and I was wondering if there is a way that I can visualize the clusters of a given Read More …

Problem Detail: I read somewhere that, if $Aleq_p B$ and $Bleq_p A$, then it is said that $Aequiv_p B$. What exactly does this mean? Is it saying that both $A$ and $B$ are the exact same level of complexity? Asked By Read More …

Problem Detail: I understand that a regular language can be specified by either regular or non-regular grammars. What is an example of a non-regular grammar for a regular language? Asked By : espertus Answered By : atulgangwar Regular Language L = {aab} Non-regular Read More …

Problem Detail: IPv6 addresses in the form of 862A:7373:3386:BF1F:8D77:D3D2:220F:D7E0 are much harder to memorize or even transcribe than the 4 octets of IPv4. There have been attempts to mitigate this, making IPv6 addresses somehow more memorable. Is there an intentionally-weak hashing Read More …

Problem Detail: Is there ANY compression type that can compress a file, and then that compressed file can be searched without uncompressing the file? Asked By : Albert Renshaw Answered By : KWillets Compressed self-indexes such as the FM Index allow arbitrary substring Read More …

Problem Detail: I’m currently an undergrad whose been amazed by what Turing has done for the world. I know there are plenty of other amazing individuals, but Turing’s work specifically has always sounded the most interesting to me and I’m finally Read More …