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: John is not running. If Karen were a sailor, then Susan is a soldier. Karen is a sailor if and only if John is running. If Karen were a sailor, then Susan is a soldier. If Susan were a soldier, then Karen is a sailor.
Karen is a sailor if and only if Susan is a soldier can be inferred via the biconditional introduction rule. Karen is a sailor if and only if Susan is a soldier can be inferred via the biconditional introduction rule. Susan is a soldier if and only if Karen is a sailor can be inferred via the biconditional introduction rule. Susan is a soldier if and only if Karen is a sailor can be inferred via the biconditional introduction rule. If Karen were a sailor, then John is running can be inferred via the biconditional elimination rule. If John goes running, then Karen is a sailor can be inferred via the biconditional elimination rule. Karen is not a sailor can be inferred via the biconditional elimination rule.