Problem Detail: I am about to implement a domain specific language for representation of social learning conventions. Part of the implementation is a formal description of a language – its ‘calculus’, symbols and logical expressions. My approach would be to describe Read More …
Category: Uncategorized
[Solved]: What’s an intuitive distinction between semi-computable problems and noncomputable problems/functions?
Problem Detail: The definitions I’ve found were highly technical and using terms I’ve never seen before. Say, I have a certain irrational number e that I get get closer and closer to with a computer and I want to determine if Read More …
[Solved]: Euclidean Steiner Tree Question in Approximation Algorithms
Problem Detail: Given $n$ points in $mathbf{R}^2$, define the optimal Euclidean Steiner tree to be a minimum (Euclidean) length tree containing all $n$ points and any other subset of points from $mathbf{R}^2$. Prove that each of the additional points must have Read More …
[Solved]: Proving that finding wheel subgraphs is NP-complete
Problem Detail: Can you help me with this problem ? Given an undirected graph $G$ and an integer $n$, prove that determining whether the graph has wheel on $n$ vertices $W_{n}$ (a wheel $W_{i}$ is such that $i$ nodes form a Read More …
[Solved]: Building functionally complete boolean circuits out of trinary logic
Problem Detail: There are some not-very-commonly considered forms of trinary logic using 3 truth values. Even entire (unusual/rare) ternary computers have been built from it. Is there some knowledge or reference of how to convert some trinary logic systems into functionally Read More …
[Solved]: Difference between graph-partitioning and graph-clustering
Problem Detail: What is the difference between graph-partitioning and graph-clustering in graph theory? Asked By : suhas bhairav Answered By : Yuval Filmus Graph partitioning and graph clustering are informal concepts, which (usually) mean partitioning the vertex set under some constraints (for example, Read More …
[Solved]: Generating all strings that a regular expressions describe
Problem Detail: I’m having trouble generating the set of strings, which a regular expressions describe. A typical regular expression can look like this: [atom_0] atom_1 (atom_2 | atorm_3 | … | atom_n-1) <var> [atom_n] Or any other combination of the following: Read More …
[Solved]: Is there a canonical definition of “pure” function?
Problem Detail: StackOverflow pointed me here, so the question might be a bit in a layman’s terms. Wikipedia defines pure functions as In computer programming, a function may be described as a pure function if both these statements about the function Read More …
[Solved]: Precise definition of term: *schema*
Problem Detail: Does the term schema, in the context of describing a structure, refer to the actual structure of the data, or the description of this structure? I.e. can I talk about the schema of an entity without a schema language? Read More …
[Solved]: Can the encodings set of a non-trivial class of languages which contains the empty set be recursively enumerable?
Problem Detail: Let $C$ be a non-trivial set of recursively enumerable languages ($emptyset subsetneq C subsetneq mathrm{RE}$) and let $L$ be the set of encodings of Turing machines that recognize some language in $C$: $$L={langle M rangle mid L(M) in C Read More …
