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 cold. Jennifer is not working. Robert is a server if and only if Jennifer is working. If Karen cooks, then Robert is a server.
It is cold and Jennifer is not working can be inferred via the conjunction rule. Jennifer is not working and it is cold can be inferred via the conjunction rule. If Robert were a server, then Jennifer is working can be inferred via the biconditional elimination rule. If Jennifer works, then Robert is a server can be inferred via the biconditional elimination rule. Robert is not a server can be inferred via the biconditional elimination rule.