arXiv subjects
Publications and source records attributed to J. Andres Montoya.
We prove that NL is strictly contained in P. We get this separation as a corollary of the following result: the set of context-free languages is not contained in NL. The reader should recall that CFL is contained in DTIME(n^3)
We prove that the class LOGSPACE (L, for short) is different from the class NP.
We investigate the computational complexity of analyzing the structural and behavioral properties of deterministic k-pebble automata, which represent a natural framework for studying minimal programmable machines. First, we provide an explicit construction of a three-pebble automaton U capable of simulating any deterministic finite automaton (DFA) on a given input word, establishing a link between pebble automata capabilities, Kolmogorov complexity, and automatic complexity. Next, we restrict our architectural framework to two-pebble programmable machines U(2,N) simulating DFAs with at most N states. We analyze the decision problem ANAL(U(2,5)), which asks whether a five-state program can separate two distinct finite words. By establishing a polynomial-time reduction from the quasi-identity checking problem for finite semigroups, we prove that ANAL(U(2,5)) is NP-complete. Finally, we explore the complexity of separating binary strings under the Exponential Time Hypothesis (ETH), showing how computational hardness implies polynomial lower bounds for the size of the smallest DFAs separating binary strings.
Let L denote the class Logpsace and NL the class NLogspace. We use logCFL to denote the closure under logspace reductions of the set of context-free languages. We prove that NL is different from logCFL. This result implies L different from Ptime and the stronger separation NL different from Ptime.
Planar automata seems to be representative of the synchronizing behavior of deterministic finite state automata. We conjecture that Černy's conjecture holds true, if and only if, it holds true for planar automata. In this paper we have gathered some evidence concerning this conjecture. This evidence amounts to show that the class of planar automata is representative of the algorithmic hardness of synchronization
We prove that the almost-entropic region of order four is not semialgebraic, we get as a corollary the well-known Theorem of Matus, which asserts that this region is not polyhedral