Discussion of definitions in "Pre-logical relations" by Honsell and Sannella, particularly the notion of a lambda applicative structure (similar to a definition in John C. Mitchell's book "Foundations for Programming Languages'). In short, lambda abstractions get interpreted in combinatory algebras by compiling away the lambda abstractions in favor of S and K combinators, which are then interpreted by the combinatory algebra. I complain about the fact that the definition of a lambda applicative structure is required to come with an interpretation function for terms (hence tying the semantics to the syntax).
En liten tjänst av I'm With Friends. Finns även på engelska.