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 late, then Jessica is a police officer. It is late if and only if Jessica is a police officer. If Jessica were a police officer, then it is late.
It is late if and only if Jessica is a police officer can be inferred via the biconditional introduction rule. Jessica is a police officer if and only if it is late can be inferred via the biconditional introduction rule. If it is late, then Jessica is a police officer can be inferred via the biconditional elimination rule. If Jessica were a police officer, then it is late can be inferred via the biconditional elimination rule.