Highest Trees of Random Mappings

We prove the exact asymptotic $1-\left({\frac{2\pi}{3}-\frac{827}{288\pi}}+o(1)\right)/{\sqrt{n}}$ for the probability that the underlying graph of a random mapping of $n$ elements possesses a unique highest tree. The property of having a unique highest tree turned out to be crucial in the solution of the famous Road Coloring Problem as well as the generalization of this property in the proof of the author's result about the probability of being synchronizable for a random automaton

Implementation of the algorithm for testing an automaton for synchronization in linear expected time

Berlinkov has suggested an algorithm that, given a deterministic finite automaton $\mathcal{A}$, verifies whether or not $\mathcal{A}$ is synchronizing in linear (of the number of states and letters) expected time. We present a modification of Berlinkov's algorithm which we have implemented and tested. Our experiments show that the implementation outperforms the standard quadratic algorithm even for automata of modest size and allow us to give a statistically accurate approximation of the ratio of non-synchronizing automata amongst all automata with a given number of states

On the probability of being synchronizable

We prove that a random automaton with $n$ states and any fixed non-singleton alphabet is synchronizing with high probability. Moreover, we also prove that the convergence rate is exactly $1-\Theta(\frac{1}{n})$ as conjectured by Cameron \cite{CamConj} for the most interesting binary alphabet case. Finally, we describe a deterministic algorithm which decides whether a given random automaton is synchronizing in linear expected time.Comment: Numerous fixes in the proo