A fully equational proof of Parikh's theorem

Aceto, Luca; Ésik, Zoltán; Ingólfsdóttir, Anna

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications, Volume 36 (2002) p. 129-153

Characteristic formulae for timed automata

Aceto, Luca; Ingólfsdóttir, Anna; Pedersen, Mikkel Lykke; Poulsen, Jan

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications, Volume 34 (2000) p. 565-584