Added:
 - Nondeterministic Z-Automaton [1]
 - ArcFactored Deterministic Z-Automaton [1]
 - ArcFactored Nondeterministic Z-Automaton [1]

[1] Johanna Björklund, Frank Drewes, Giorgio Satta: Z-Automata for
Compact and Direct Representation of Unranked Tree Languages
https://doi.org/10.1007/978-3-030-23679-3_7



Co-authored-by: Tomáš Pecka <tomas.pecka@fit.cvut.cz>