p ” and “ p or q ” is given in detail at the beginning of Principia Mathematica . This gives all that is wanted when the propositions which are arguments to our truth-function are given by enumeration. Wittgenstein, however, by a very interesting analysis succeeds in extending the process to general propositions, i.e. to cases where the propositions which are arguments to our truth-function are not given by enumeration but are given as all those satisfying some condition. For example, let f ⁡ x be a propositional function ( i.e. a function whose values are propositions), such as “ x