Questions tagged [transducers]

32 questions
11
votes
3 answers

Algorithms for minimizing Moore automata

Brzozowski's algorithm can be extended to Moore automata but its time complexity is exponential in general. Is there any other algorithm for minimization of Moore automata? What are the running times of these algorithms if any?
6
votes
1 answer

Can Tree Transducers Self-Interpret?

Is it possible for MSO graph/tree transducers to reflect themselves, namely to create an interpreter of tree/graph transducers using tree/graph transducers? If yes, I'll be happy for some design guidelines.
Troy McClure
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6
votes
1 answer

How do I construct an FSA that accepts the non-fixed points of a finite state transducer?

Given a finite state transducer $F$, I'm interested in constructing a finite state automaton that accepts the set of input strings $x$ such that $F(x) \ne x$. My questions are: Is this set always a regular language? If so, is there a standard…
4
votes
1 answer

NL and NP compute different binary relations, so what?

Let the binary relation computed by a nondeterministic transducer be the relation between input strings and the possible output strings the transducer can produce (and accept) for the given input string. It is easy to see that the nondeterministic…
4
votes
1 answer

Is the power of a natural number logspace-computable?

Given a constant $n\in\mathbb{N}_+$, is the simple power function $$ λ\,x\in\mathbb{N}_+.\,x^n $$ logspace computable by a logspace transducer (which has a read-only input tape, a working read-write tape (on which the transducer is allowed to use…
user111225
3
votes
1 answer

Are finite state transducers and Mealy machines the same?

There are several versions of the definitions of the finite state transducer (FST) and the Mealy machine. Some of the definitions are almost same, while others have a few differences. However, it seems that both are a kind of deterministic finite…
Blanco
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3
votes
0 answers

How to apply insights from the theory of codes to alternating codes?

The book Theory of codes by J. Berstel and D. Perrin from 1985 studies variable-length codes. The focus is less on error-correction and compression, but more on algebraic properties, synchronization and connections to automata (especially…
Thomas Klimpel
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2
votes
0 answers

Which transducer models replacement in regex?

I am looking for the right transducer which allows to translate a sequence of literals into a sequence of same literals (or a subset of them) in arbitrary order. For example: ABC => CAB, which, with simple production rules: A->a, B->b, C->c,…
2
votes
1 answer

Complexity of identifying "generic & distinguishable" Moore machines

Consider a non-deterministic Moore machine with input alphabet $\Sigma \newcommand\OO{\mathcal{O}} \newcommand\o{\mathfrak{o}} \newcommand\PP{\mathcal{P}}$ and output alphabet $\OO$, a set of states $S$, with output function $\o: S\to \OO$ and with…
2
votes
0 answers

Regular string relations - proof of correctness

Let $T \subseteq \Sigma^* \times \Sigma^*$ be a regular (rational) relation. We define the obligatory rewrite relation over $T$ as follows: $$ R^{obl}(T) := N(T) \cdot (T \cdot N(T))^* $$ $$ N(T) := Id(\Sigma^* \setminus (\Sigma^* \cdot dom(T)…
2
votes
1 answer

Is it possible to constract Moore or Mealy machine with a different size of input and output?

Is it possible to constract Moore or Mealy machine to take input tape: 0011 and output: 00001111 (or vice versa). In other words, input and output have different size. I want to construct FSMs to produce different transformation patters: copy 2…
Oleg Dats
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1
vote
0 answers

Regexp substitution and finite-state transducers

Many programming languages support a "regular expression substitution" operation: if r is a regular expression and s, t are strings, sub(s, r, t) finds the first substring of s that matches the regexp r and replaces it with t. Can this operation…
D.W.
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1
vote
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almost realtime push down relation vs realtime pushdown relation?

Almost realtime pushdown relation pop a symbol for each empty step. Realtime pushdown relation does not perform any empty step. What do they mean by empty step?
1
vote
2 answers

What is the expressive power of finite-state transducers and pushdown transducers?

One would assume that a finite state transducer can perform any translation such that the resulting string is from a regular grammar. Similarly, that a pushdown transducer can generate strings from CFG grammars. I am, however, unsure about this…
S0rin
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1
vote
0 answers

Finite-state transducer to accept $i$'th word of DFA

If I have a DFA $D$ that accepts some regular language $L$, is it possible to construct some finite-state transducer $T$ that takes in an index $i$, and puts out the $i$'th word in $L$, ordered lexicographically? I know from this paper that you can…
Jake
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