The course begins with a simple system called sentential or propositional logic, which despite its simplicity captures a significant range of important arguments. The course then focuses on ...

A propositional system of modal logic is second-order if it contains quantifiers ∀p and ∃p, which, in the standard interpretation, are construed as ranging over sets of possible worlds (propositions).

Special attention is paid to the most basic logic in this hierarchy, the pure "intelim logic", which satisfies all the requirements of a natural deduction system (allowing both introduction and ...