This document discusses the concepts of phrase and sentence meaning, extension and intension, and sense and reference.
It explains that the meaning of phrases and sentences depends on both the meaning of the individual words as well as how those words are structurally combined. It also describes intension as the internal content or formal definition of a term, while extension refers to the range of objects to which a term applies. Finally, it distinguishes sense, which deals with relationships within language, from reference, which involves the relationship between language and real-world objects. Sense is the place of an expression within a system of semantic relationships, while reference can be either variable, applying to different types of objects, or constant, referring to the same