 Metalogical properties. The nice metatheorems that \(\mathbf{IFL}\) shares with \(\mathbf{FO}\) are lost: Compactness, Löwenheim-Skolem property, separation theorem, and the existence of a complete disproof procedure all fail for \(\mathbf{EIFL}\) (Hintikka 1991: 49, 1996: 189). No self-applied truth-predictate is possible for \(\mathbf{EIFL}\). The definition of such a truth-predicate would have to contain the clause