 In Carnap’s work after 1935, it is important to distinguish between two different parts of the semantic enterprise. On the one hand, there are the repeated attempts to pin down the inferential relations between observation-statements and more general ones within the general framework of semantics. In this work, meaning and reference are considered particularly as they concern the empirical content (or meaning) of general statements, whether empirical generalizations or theories of more universal scope. This includes “Testability and Meaning” (Carnap 1936–37), the later work on the theoretical language (Carnap 1956a, 1959a), and much of the work on inductive logic (see  section 8  below). On the other hand, there is the construction of the semantic framework itself, its logical delineation and development; even if this was in principle to serve the first purpose, it became in effect a distinct project. This includes the Studies in Semantics, the modal logic systems (Carnap 1946), and the later version of his logic textbook, Einführung in die symbolische Logik (Carnap 1968b). We discuss this second component in  section 6.2,  immediately following, and the first component in  section 8  below.