6 papers
An algebraic characterisation of Eve-positional languages
Thomas Colcombet, Olivier Idir
We present a new algebraic characterisation of Eve-positionality for -regular languages. It involves only a limited number of elementary local properties to be checked. An -r…
Eve-positional languages: putting order into Büchi automata
Olivier Idir
An -regular language is Eve-positional if, in all games with this language as objective, the existential player can play optimally without keeping any information from the previ…
Using games and universal trees to characterise the nondeterministic index of tree languages
Olivier Idir, Karoliina Lehtinen
The parity index problem of tree automata asks, given a regular tree language and a set of priorities , is -feasible, that is, recognised by a nondeterministic parity…
Mostowski Index via extended register games
Olivier Idir, Karoliina Lehtinen
The parity index problem of tree automata asks, given a regular tree language L, what is the least number of priorities of a nondeterministic parity tree automaton that recognises…
Explorable Parity Automata
Emile Hazard, Olivier Idir, Denis Kuperberg
We define the class of explorable automata on finite or infinite words. This is a generalization of History-Deterministic (HD) automata, where this time non-deterministic choices c…
On the Minimisation of Deterministic and History-Deterministic Generalised (co)Büchi Automata
Antonio Casares, Olivier Idir, Denis Kuperberg +2
We present a polynomial-time algorithm minimising the number of states of history-deterministic generalised coBüchi automata, building on the work of Abu Radi and Kupferman on coBü…