The Scottish logician Hugh MacColl (1837 - 1909) received his В.A. at the University of London and taught mathematics in Boulogne for most of his life.
¶ MacColl argued that the basic relation in logic is not class inclusion, but implication between propositions, and in two series papers, the first on "The Calculus of Equivalent Statements" published in the late 1870s in Proceedings of the London Mathematical Society, the second on "Symbolic Reasoning" published in Mind from 1897 to 1906 and collected in Symbolic Reasoning and Its Applications, he developed the details for this "pure [propositional] logic". In carrying out this work he was instrumental in developing formal non-classical, particularly modal, logic, and his definition of 'p implies q' anticipated C. I. Lewis's definition of strict implication.