| Description: |
This is an introduction to modal logic and some of its
applications within philosophy. We will begin by studying the
propositional modal logics K, K4, T, B, S4, and S5, both in terms of
their deductive systems and in terms of their Kripke semantics.
Soundness and completeness theorems for each of these logics will be
proved in some detail. In terms of modal predicate logic, we will focus
on various versions of S5, taking a primarily model-theoretic approach.
We'll discuss some well-known expressive limitations of quantified S5
and consider some ways of alleviating these, including the introduction
of an actuality operator in two-dimensional modal logic. Time
permitting, we'll also cover the basics of the logic of counterfactual
conditionals and/or tense logic.
|