Descriptional Complexity of Formal Systems

The Alphabetic Complexity in Homomorphic Definitions of Word, Tree and Picture Languages.- Ranking Binary Unlabelled Necklaces in Polynomial Time.- On the Power of Recursive Word-Functions without Concatenation.- Clusters of Repetition Roots Forming Prefix Chains.- Nearly k-Universal Words - Investigating a Part of Simon's Congruence.- State Complexity of Binary Coded Regular Languages.- Reset Complexity and Completely Reachable Automata with Simple Idempotents.- On the Descriptional Complexity of the Direct Product of Finite Automata.- Operations on Subregular Languages and Nondeterministic State Complexity.- On Simon's Congruence Closure of a String.- Approximate NFA Universality Motivated by Information Theory.- Lazy Regular Sensing.- State Complexity of Finite Partial Languages.- Yet Another Canonical Nondeterministic Automaton.- Union-Complexities of Kleene Plus Operation.