Finally, I have finished drafting and proofreading a book about Lesniewski's systems. To some extent it is based on my PhD thesis, but it has gone through major revisions and around 1/3 of it is new material. Anyway, if you feel like accessing the draft in exchange for a promise to let me know what you think by June 2012, please get in touch. Synopsis. Stanisław Leśniewski (1886--1939), a Polish logician, a representative of the Lvov-Warsaw school and Alfred Tarski's PhD supervisor, developed his philosophically (and nominalistically) motivated foundations of mathematics as an alternative to the system of Principia Mathematica . He constructed three systems: a generalized propositional calculus called Protothetic , his own (higher-order) logic of predication dubbed Ontology , and a theory of parthood known as Mereology . This books presents, explicates and critically discusses Leśniewski's work and some more recent developments stemming from it. In contrast to the ...