Coalgebra automata are finite automata that operate on (possibly) infinite objects which are represented as pointed coalgebras. Examples from the literature such as automata on infinite words, trees and graphs can be seen as coalgebra automata.

In my talk I will first recall the definition of a coalgebra automaton. Then I will show how we can prove certain closure properties such as closure under union, intersection and projection in a uniform way for all coalgebra automata. Moreover I will sketch the proof of the fact that coalgebra automata are closed under alternation, i.e. that to any alternating coalgebra automaton there exists an equivalent non-deterministic one.