Abstract

Roman Suszko introduced a broad class of languages into the litera- ture of logic. In honour of L. Wittgenstein Suszko named these languages W-languages. Syntax, semantics and consequence operations in these lan- guages are based on the famous ontological principle: whatever exists is either a situation, or an object, or a function. The distinguishing property of W-languages is that they contain: sentential and nominal variables, an identity connective and an identity predicate. The intended interpretation of W-languages is such that: sentential variables range over universum of situations, nominal variables range over universum of objects. All other symbols in these languages, except sentential and nominal variables, are interpreted as symbols of some functions dened in both universum of sit- uations and universum of objects. The identity connective corresponds to the identity relation between situations, and the identity predicate corre- sponds to the identity relation between objects