Skip to main content

All Questions

Filter by
Sorted by
Tagged with
4 votes
0 answers
170 views

Corollaries of Kleene's Theorem (Regular Languages)

Kleene's theorem that finite automata (specifically, nondeterministic) are expressively equivalent to regular expressions seems to be a powerful and not immediately obvious tool for untangling the ...
TomKern's user avatar
  • 429
2 votes
0 answers
47 views

Relation between indexed languages (OI-macro or context-free tree) and scattered context languages

I'm not sure about the relation between indexed languages (generated by indexed grammars--Aho) and scattered context languages (generated by scattered context grammars--J Hopcroft). I think that ...
Nate's user avatar
  • 21
4 votes
1 answer
2k views

Deciding equivalence of regular languages

Given two regular expressions $R$ and $S$ on an alphabet $\Sigma$ it is possible to decide their equivalence as follows: build two finite automata $M_R$ and $M_S$ such that $L(R) = L(M_R)$ and $L(S) =...
Alberto's user avatar
  • 105
1 vote
2 answers
2k views

Translate a buchi automaton to LTL

How can I translate a Büchi automaton A to LTL(linear temporal logic) if $L(A)$ is definable in the LTL? MY idea is : Büchi automaton $A$ ===> QPTL ===> LTL I know that given any Buchi ...
LimaoLogic's user avatar
4 votes
2 answers
2k views

Are context-free languages with context-free complements necessarily deterministic context-free?

Let $L \subseteq A^\star$ be a formal language over $A$ generated by a context-free grammar, and $L' = A^\star - L$ be the relative complement in $A^\star$. If $L$ and $L'$ are both context-free, are ...
Nick Loughlin's user avatar
3 votes
1 answer
528 views

Study of free monoids of the recursive S. Eilenberg.

Compared to the usual treatises on recursion (eg, Rogers H. "Computability and Undecidability." McGraw-Hill, New York) the book of Samuel Eilenberg & Calvin C. Elgot "Recursiveness" treats such ...
Buschi Sergio's user avatar
12 votes
3 answers
877 views

Complementation of $\omega$-regular languages in reverse mathematics

Does anyone know where Büchi's theorem that $\omega$-regular languages are closed under complementation fits into the reverse-mathematics classification scheme? That is, is it equivalent over $\...
Alex Simpson's user avatar