Abstract This paper investigates the effectiveness of identification task on retention situation-bound utterances (SBUs) in Chinese as a foreign language (CFL). The participants were Italian CFL learners with different lengths learning experience, divided into an experimental and control group. target SBUs selected by means discourse completion questionnaire previously submitted to native speak...

We solve an open problem concerning syntactic complexity: We prove that the cardinality of the syntactic semigroup of a suffix-free language with n left quotients (that is, with state complexity n) is at most (n − 1) + n − 2 for n > 6. Since this bound is known to be reachable, this settles the problem. We also reduce the alphabet of the witness languages reaching this bound to five letters ins...

We prove that the topological entropy of subshifts having decidable language is uncomputable in the following sense: For no error bound less than 1/4 does there exists a program that, given a decision procedure for the language of a subshift as input, will approximate the entropy of the subshift within the error bound. In addition, we prove that not only is the topological entropy of sofic shif...

The neighbourhood of a regular language with respect to the prefix, suffix and subword distance is always regular and a tight bound for the state complexity of prefix distance neighbourhoods is known. We give upper bounds for the state complexity of the neighbourhood of radius k of an n state DFA (deterministic finite automaton) language with respect to the suffix distance and the subword dista...

We show that any concurrent zero-knowledge protocol for a non-trivial language (i.e., for a language outside BPP), whose security is proven via black-box simulation, must use at least ~ (log n) rounds of interaction. This result achieves a substantial improvement over previous lower bounds, and is the rst bound to rule out the possibility of constant-round concurrent zero-knowledge when proven ...

The profinite topology is used in rational languages classification. In particular, several important decidability problems, related to the Malcev product, reduce to the computation of the closure of a rational language in the profinite topology. It is known that given a rational language by a deterministic automaton, computing a deterministic automaton accepting its profinite closure can be do...

We show that any one-counter automaton with n states, if its language is non-empty, accepts some word of length at most O(n). This closes the gap between the previously known upper bound of O(n) and lower bound of Ω(n). More generally, we prove a tight upper bound on the length of shortest paths between arbitrary configurations in onecounter transition systems. Weaker bounds have previously app...

In this paper‎, ‎using the discrete Fourier transform in the finite-dimensional Hilbert space C^n‎, ‎a class of nonRieszable equal norm tight frames is introduced ‎and‎ using this class, a bound for Fiechtinger Conjecture is presented. By the Fiechtinger Conjecture that has been proved recently, for given A,C>0 there exists a universal constant delta>0 independent of $n$ such that every C-equal...