chapter  8
9 Pages

The Propositional Calculus

WithG. E. Hughes, D. G. Londey

In Chapter 3 we remarked that the Propositional Calculus (‘PC’ for short) has as its field the class of all propositional schemata which contain no variables other than propositional variables, and no operators other than truth-functional proposition-forming operators. In considering various common forms of inference, we have examined a few of these schemata; and we have given a fairly informal account of the conditions which a properly put together schema (whether valid or not) must satisfy. (E.g. ‘⊃’ must have two arguments.)