 Mortensen (1984), who considers AT′, explains that Routley’s characterization of AT′ is “not particularly intuitively enlightening” and points out that in certain logics with a ternary relational models semantics another characterization of AT′ is available, namely the condition that for every model M the set CA := {s : M, s ⊨ A and M, s ⊭ ~A} is non-empty. Like Routley’s non-recursive requirement that G(A, t) implies M, t ⊨ A, Mortensen’s condition is not a purely structural condition, since it mentions the truth relation ⊨. Mortensen (1984, p. 114) maintains that the condition CA ≠ ∅ “is closest to the way we think of Aristotle,” and emphasizes that for a self-inconsistent proposition A, the set CA must be empty, whence AT′ is to be denied. Mortensen also critically discusses the addition of AT′ to the relevance logic E. In this context, AT′ amounts to the condition that no implication is true at the world T*.