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: Patricia is an astronaut if and only if Patricia is playing squash. If James goes running, then Patricia is playing squash. James is not running. If Patricia plays squash, then James is running.
Patricia is not playing squash can be inferred via the modus tollens rule. James is running if and only if Patricia is playing squash can be inferred via the biconditional introduction rule. Patricia is playing squash if and only if James is running can be inferred via the biconditional introduction rule. If Patricia were an astronaut, then Patricia is playing squash can be inferred via the biconditional elimination rule. If Patricia plays squash, then Patricia is an astronaut can be inferred via the biconditional elimination rule.