Andrzej Pietruszczak is a Full Professor of Logic at the Department of Logic, Nicolaus Copernicus University in Toruń, Poland. He is the author of three books:  „A Quantifier-free Calculus of Names, Systems and their Metatheory”,  „Metamereology” and  „Foundations of the Theory of Parthood” (all in Polish) and over 70 papers devoted to mereology, classical and non-classical logic and set theory published, amongst others, in „Bulletin of Symbolic Logic”,  „Fundamenta Informaticae”, „Notre Dame Journal of Formal Logic” and  „Studia Logica”. He is a cofounder and an editor-in-chief of the quarterly Journal  „Logic and Logical Philosophy” (Emerging Sources Citation Index – Clarivate Analytics, ERIH, Scopus).