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: David is reading a book or Thomas is playing a game. If David reads a book, then Elisabeth is climbing a mountain. John is driving a car. Elisabeth is not climbing a mountain.
David is not reading a book can be inferred via the modus tollens rule. John is driving a car and Elisabeth is not climbing a mountain can be inferred via the conjunction rule. Elisabeth is not climbing a mountain and John is driving a car can be inferred via the conjunction rule.