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: It is raining if and only if Karen is driving a car. Karen is not driving a car. If it is sunny, then it is raining. If it rains, then it is sunny.
It is sunny if and only if it is raining can be inferred via the biconditional introduction rule. It is raining if and only if it is sunny can be inferred via the biconditional introduction rule. If it rains, then Karen is driving a car can be inferred via the biconditional elimination rule. If Karen drives a car, then it is raining can be inferred via the biconditional elimination rule. It is not raining can be inferred via the biconditional elimination rule.