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: Jessica is not taking a plane. It is sunny if and only if James is running. If it is sunny, then Jessica is taking a plane.
It is not sunny can be inferred via the modus tollens rule. If it is sunny, then James is running can be inferred via the biconditional elimination rule. If James goes running, then it is sunny can be inferred via the biconditional elimination rule.