“…The relational model [37,17] is a simple denotational semantics of the λ-calculus induced by the relational model of linear logic, via the representation of the λ-calculus in linear logic. It is a paradigmatic model, underlying many others [30,31,24,45,48], mainly studied by Ehrhard and his students and co-authors [38,18,21,16,32,33,34,26,47,46,49,15], the importance of which has emerged slowly. One of its features is that it admits a handy presentation via an intersection type system.…”