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: If it is overcast, then Jennifer is a lawyer. If it is overcast, then Patricia is driving a car. If Jennifer were a lawyer, then it is overcast. If Patricia drives a car, then Jennifer is a lawyer.
If it is overcast, then Jennifer is a lawyer can be inferred via the transitivity rule. If Jennifer were a lawyer, then Patricia is driving a car can be inferred via the transitivity rule. If Patricia drives a car, then it is overcast can be inferred via the transitivity rule. It is overcast if and only if Jennifer is a lawyer can be inferred via the biconditional introduction rule. Jennifer is a lawyer if and only if it is overcast can be inferred via the biconditional introduction rule.