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: Elisabeth is driving a car. If Elisabeth drives a car, then it is cold. David is working if and only if it is cold.
It is cold can be inferred via the modus ponens rule. If David works, then it is cold can be inferred via the biconditional elimination rule. If it is cold, then David is working can be inferred via the biconditional elimination rule.