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: Karen is sleeping if and only if James is a taxi driver. For all x_19, x_19 is not sad. Jessica is sad or it is cloudy. If James were a taxi driver, then it is not cloudy.
If Karen sleeps, then James is a taxi driver can be inferred via the biconditional elimination rule. If James were a taxi driver, then Karen is sleeping can be inferred via the biconditional elimination rule.