Canonical models of CJ 2022 axioms #
We demonstrate that Carmo and Jones 2022 axioms 5(a)(b)(c)(g) do not imply their 5(d) or 5(f). We also show that 5(a)(b)(c)(d)(f)(g) together do not imply 5(e). This is done using two-world model counterexamples.
None of the other axioms imply 5a: consider the no-worlds model (which contradicts CJ axiom 1) with ∅ ∈ ob ∅.
We show that the system has arbitrarily large models.