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: Mary is working if and only if Richard is driving a car. Thomas is not reading a book. Thomas is reading a book if and only if Richard is driving a car. If Thomas plays tennis, then Mary is working.
If Mary works, then Richard is driving a car can be inferred via the biconditional elimination rule. If Thomas reads a book, then Richard is driving a car can be inferred via the biconditional elimination rule. If Richard drives a car, then Mary is working can be inferred via the biconditional elimination rule. If Richard drives a car, then Thomas is reading a book can be inferred via the biconditional elimination rule. Richard is not driving a car can be inferred via the biconditional elimination rule.