Mutually Accepting Capacitated Automata -- Bad pictures: some structural properties related to overlaps -- Regular Expression Length via Arithmetic Formula Complexity -- Crisp-determinization of Weighted Tree Automata over Additively Locally Finite and Past-finite Monotonic Strong Bimonoids is Decidable -- On the Power of Generalized Forbidding Insertion-Deletion Systems -- State Complexity Bounds for the Commutative Closure of Group Languages -- Multiple Concatenation and State Complexity (Extended Abstract) -- Combining Limited Parallelism and Nondeterminism in Alternating Finite Automata -- Longer shortest strings in two-way finite automata -- Iterated Uniform Finite-State Transducers: Descriptional Complexity of Nondeterminism and Two-Way Motion -- Descriptional Complexity of Winning Sets of Regular Languages -- State complexity of GF(2)-inverse and GF(2)-star on binary languages -- Complexity of Two-dimensional Rank-reducing Grammars -- Palindromic Length of Words with Many Periodic Palindromes -- Operational Complexity of Straight Line Programs for Regular Languages -- Classifying ω-Regular Aperiodic k-Partitions -- Recognition and Complexity Results for Projection Languages of Two-Dimensional Automata -- On the Generative Power of Quasiperiods -- Insertion-Deletion Systems With Substitutions II.

This book constitutes the proceedings of the 22nd International Conference on Descriptional Complexity of Format Systems, DCFS 2020, which was supposed to take place in Vienna, Austria, in August 2020, but the conference was canceled due to the COVID-19 crisis. The 19 full papers presented in this volume were carefully reviewed and selected from 31 submissions. They deal with all aspects of descriptional complexity and costs of description of objects in various computational models, such as Turing machines, pushdown automata, finite automata, grammars, and others.