ABSTRACT
Semantics is a term with many meanings. In this chapter it refers to a formal analysis of the meaning of ACT expressions. It is not "semantics" as that term is most often used in cognitive psychology. That is, semantics in this chapter is not a psychological theory about how subjects comprehend sentences, represent meanings, or reason about meanings. Rather it is a metatheoretical enterprise. The semantics in this chapter has the same relation to a psychological theory as does the formal study of stochastic processes. That is, it provides us with a tool to study ACT, which is the psychological theory.
