<we><edit> <!-- questions and answers -->
randomized-algorithms
terminology
semantics
arithmetic
neural-networks
quantum-computing
linear-programming
sets
discrete-mathematics
correctness-proof
turing-machines
graphs
formal-languages
greedy-algorithms
reference-request
efficiency
hash-tables
graph-theory
parsers
memory-management
functional-programming
proof-techniques
search-trees
pushdown-automata
image-processing
formal-languages
Use the pumping lemma to show the language is not regular
formal-languages
regular-languages
pumping-lemma
Is square numbers written in binary a regular language?
formal-languages
regular-languages
automata
finite-automata
How do I develop a structured work method for theoretical computer science?
complexity-theory
formal-languages
computability
Given are $4$ languages. What kind of language are they (regular, context free, context sensitive..)?
formal-languages
regular-languages
formal-grammars
chomsky-hierarchy
Is language equality for linear context-free grammars decidable?
formal-languages
context-free
formal-grammars
Does closure under union and concatenation imply closure under Kleene star?
formal-languages
turing-machines
regular-languages
automata
How do you get a regex from this DFA?
formal-languages
automata
finite-automata
regular-expressions
Recursive definition of a language $ L $ over $ \{a,b\} $
complexity-theory
formal-languages
regular-languages
recursion
The difference between absurd reasoning and contraposal reasoning
formal-languages
automata
How can i prove this language is not context free?
formal-languages
context-free
pumping-lemma
How to define a language for an independent set problem of a graph?
formal-languages
graphs
Prove or disprove: Complement of language $L=\left\{baba^2ba^3b...ba^{n-1}ba^nb \, | \, n \geq 1\right\}$ is context-free
formal-languages
context-free
formal-grammars
Finding whether the language is CFL or regular
formal-languages
regular-languages
Set of all countably infinite strings over a finite alphabet >1
formal-languages
Reduction from $3SAT$ to $PARTITION$
formal-languages
np-complete
reductions
Understanding definitions of Deterministic Context Free Grammar and Deterministic Pushdown Automaata
formal-languages
automata
context-free
formal-grammars
pushdown-automata
How to prove the well-Definedness of the Operation $.\:$?
formal-languages
How to prove or disprove the well-Definedness of the Operation $.\:$?
formal-languages
Pumping lemma with multiple of prime number + a constant
formal-languages
pumping-lemma
How can the intersection of CFLs and REGs be CFL if REG is a proper subset of CFL?
formal-languages
regular-languages
context-free
chomsky-hierarchy
Empty words in regular languages
formal-languages
regular-languages
regular-expressions
What does $|w|$ mean in the statement " $|w|$ where $w \in L \subset \Sigma^*$"?
formal-languages
notation
Unambiguous grammar for regular expressions
formal-languages
context-free
regular-expressions
Are there descriptive examples of the architecture of standard content management systems, that provide full user rights handling?
formal-languages
programming-languages
DFA accepting strings with at least three occurrences of three consecutive 1's
formal-languages
finite-automata
formal-grammars
compilers
Is there a grammar (not necessarily context-free) that generates $n^2$ zeroes?
formal-languages
Prove that $\{1^m+1^n = 1^{m+n}\}$ is not regular using Myhill–Nerode
formal-languages
regular-languages
Find any kind of grammar for the language
formal-languages
regular-languages
automata
finite-automata
formal-grammars
Closure of context-free languages under "removal of a regular language from the right"
formal-languages
context-free
Construct an equivalent NFA for the given regular grammar
formal-languages
regular-languages
automata
finite-automata
formal-grammars
Is this language $LL(1)$ parseable?
formal-languages
context-free
parsers
Language Accepted by a Turing Machine with a Useless State?
formal-languages
turing-machines
automata
reductions
undecidability
How was Idris' `rewrite` implemented?
formal-languages
term-rewriting
Is unary language with polynomial power context sensitive?
formal-languages
context-sensitive
How to compare the efficiency of two encoding schemes or hypothesis languages?
formal-languages
terminology
efficiency
coding-theory
encoding-scheme
What is the relationship between problems and languages?
formal-languages
If $L$ is recursively enumerable (or recursive) then so is $L′$
formal-languages
computability
reductions
closure-properties
Language of CFG: $S \to aS | aSbS | \varepsilon$
formal-languages
context-free
proof-techniques
Use the pumping lemma to prove that {www} is not context-free
formal-languages
context-free
pumping-lemma
Is there a regular grammar for the language $\{ w : |w|_0 = |w|_1 \}$?
formal-languages
formal-grammars
How can you define the notion of "state" using only a type theory language?
formal-languages
Short quiz about Myhill-Nerode theorem
formal-languages
regular-languages
automata
finite-automata
The importance of normal forms like Chomsky normal form for CFGs
formal-languages
context-free
formal-grammars
normal-forms
If $L$ is recursive then so is $L^*$, and vice versa
formal-languages
turing-machines
undecidability
How can I find the center character of a two-tape Turing Machine in n transitions?
formal-languages
turing-machines
Removing epsilon transition from the grammar. What's the difference between accepting languages?
formal-languages
context-free
formal-grammars
Prove grammars with long derivations generate infinite languages
formal-languages
context-free
formal-grammars
Give an example of a language whose Myhill-Nerode equivalence relation is such that if $x,y \in \{0,1\}^*$ with $x \neq y$, then $[x] \neq [y]$
formal-languages
Equivalence classes of regular languages
formal-languages
regular-languages
Why is $L= \{ 0^n 1^n | n \geq 1 \}$ not regular language?
formal-languages
regular-languages
intuition
Are empty-set languages recursively enumerable?
formal-languages
turing-machines
Sets whose decimal expansions form a regular language
formal-languages
regular-languages
integers
Grammar types constraint after adding a couple of types (and a statement involving them) to a "typeless" language
formal-languages
formal-grammars
programming-languages
type-theory
python
Context-free Language - Pumping Lemma or Push-down
formal-languages
context-free
pumping-lemma
pushdown-automata
Is the language in the description context free?
formal-languages
Regular expression for even/odd string on alphabet
formal-languages
regular-expressions
Are URI's a regular language?
formal-languages
regular-languages
CFG grammar with fixed number of "distinguished" terminals
formal-languages
terminology
reference-request
formal-grammars
Is the language of words containing equal number of 001 and 100 regular?
formal-languages
regular-languages
pumping-lemma
What is the minimal pumping length of this string $(01)^*$
formal-languages
regular-languages
pumping-lemma
Show that kleene plus language is a regular language by describing how you build a DFA or NFA for it
formal-languages
automata
finite-automata
Number of words in $L$ of length $n$?
formal-languages
proof-assistants
What kind of languages can be recognized by a restricted one-tape deterministic Turing Machine?
formal-languages
automata
context-sensitive
linear-bounded-automata
How to show that a language is strictly context sensitive
formal-languages
context-free
pumping-lemma
What is the transitive and reflective closure of the derivation relationship?
formal-languages
logic
Converting CFG to CNF
formal-languages
natural-language-processing
Show that the "first half" language is regular by describing how you build a DFA or NFA for it
formal-languages
automata
finite-automata
DFA or NFA Construction
formal-languages
finite-automata
Why don't we use $ as end marker for input in PDA?
formal-languages
automata
How do you translate these 2 regular languages in words correctly?
formal-languages
regular-languages
automata
finite-automata
Meaning of $|w| ≡ 2 \mod 3$
formal-languages
formal-grammars
modular-arithmetic
What's the language of the NFA?
formal-languages
regular-languages
automata
finite-automata
Non-deterministic Turing Machine recognizing a context-free Language
formal-languages
turing-machines
nondeterminism
algorithm-design
Is the problem of deciding whether a Context free grammar generates exactly K strings is decidable?
formal-languages
Fundamental algorithms in formal language-automata theory
algorithms
formal-languages
automata
Does rice theorem applies to languages only or does it apply to machines as well?
formal-languages
turing-machines
When is the empty word part of A+?
formal-languages
When is the empty word part of $A^+$?
formal-languages
proof-techniques
kleene-star
Let $L_1$ be a DCFL and $L_2$ be recursive language. Is $L_1 \cap L_2$ a DCFL?
formal-languages
NFA: If alphabet {0,1} is given, are you allowed to build a NFA with only 0?
formal-languages
regular-languages
automata
finite-automata
Physical significance of pumping length in pumping lemma
formal-languages
pumping-lemma
Are the regular languages closed against injecting single letters?
formal-languages
regular-languages
closure-properties
$m/p$-equivalence holds after union with an arbitrary finite language
complexity-theory
formal-languages
turing-machines
reductions
polynomial-time
Pumping lemma for context-free languages - Am I doing it right?
formal-languages
context-free
pumping-lemma
Prove that $L_1 = \{\, 0^m 1^k 2^n \,\vert\, \lvert m - n \rvert = k \,\}$ is not regular using Pumping lemma
formal-languages
pumping-lemma
Does this grammar generate regular language?
formal-languages
regular-languages
Proving union of 2 regular languages is regular
formal-languages
finite-automata
Grammar for ${a^n b^n c^{n+m}}$
formal-languages
formal-grammars
Can a linear bounded automata accept empty string?
formal-languages
If L1 ⊆ L2 and L2 is regular, then L2 − L1 is regular
formal-languages
regular-languages
closure-properties
Create DFA with String of {a,b}
formal-languages
regular-languages
regular-expressions
proving {$a^ib^jc^k : j = i \lor j = k$} is not regular
formal-languages
regular-languages
Proving that no two state DFA accept the language L = {$0^i : \forall i \ge 0$} $\lor$ {$^i : \forall i \ge 0$}
formal-languages
finite-automata
Are linear languages always unambiguous?
formal-languages
context-free
ambiguity
Concatenation of $a^p$ and $a^m$ where $p$ and $m$ are primes, is irregular?
formal-languages
regular-languages
How do you prove that the set of decimal representation of the 4 divisble natural numbers is regular?
formal-languages
regular-languages
automata
finite-automata
proof-techniques
Prove or disprove that the following language is context-free
formal-languages
context-free
pumping-lemma
Show that $L = \{1^n w 1^n | n > 0 \text{ and } w ∈ \{0,1\}^*\}$ is regular
formal-languages
regular-languages
regular-expressions
Regular language such that L(r) = L(r₁) L(r) ∪ L(r₂)
formal-languages
regular-languages
Classes of languages for which the language $\{a_1^n \cdots a_k^n \mid n \geq 0\}$ is in the language for $k$ but not $k+1$
formal-languages