On Friday July 2, 2021, our colleague Luca Aceto from Reykjavik University delivered an invited talk at LICS 2021 entitled In search of lost time: Axiomatising parallel composition in process algebras. An article with the same title, authored by Luca Aceto, Elli Anastasiadi, Valentina Castiglioni, Anna Ingolfsdottir and Bas Luttik appeared in the proceeding. Luca’s excellent LICS 2021 presentation is still available on YouTube.