What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: If Joseph were an artist, then John is taking a plane. If John takes a plane, then it is late. It is late. It is late if and only if Joseph is an artist.
If Joseph were an artist, then it is late can be inferred via the transitivity rule. If it is late, then Joseph is an artist can be inferred via the biconditional elimination rule. If Joseph were an artist, then it is late can be inferred via the biconditional elimination rule.