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 snowing if and only if Susan is taking a plane. If Susan takes a plane, then Susan is sleeping. Thomas is not reading a book. Thomas is reading a book if and only if Susan is sleeping.
If it snows, then Susan is taking a plane can be inferred via the biconditional elimination rule. If Thomas reads a book, then Susan is sleeping can be inferred via the biconditional elimination rule. If Susan takes a plane, then it is snowing can be inferred via the biconditional elimination rule. If Susan sleeps, then Thomas is reading a book can be inferred via the biconditional elimination rule. Susan is not sleeping can be inferred via the biconditional elimination rule.