 To rule a semantic theory like this one non-compositional, we need to demand that the meaning of a complex expression be determined by its immediate structure, and the meanings of its immediate constituents. (The immediate structure of an expression is the syntactic mode its immediate constituents are combined. e is an immediate constituent of \(e'\) iff e is a constituent of \(e'\) and \(e'\) has no constituent of which e is a constituent.)