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: If Mary goes running, then Linda is reading a book. Elisabeth is driving a car. If Linda reads a book, then Mary is running. Mary is running if and only if it is snowing. It is not snowing.
Elisabeth is driving a car and it is not snowing can be inferred via the conjunction rule. It is not snowing and Elisabeth is driving a car can be inferred via the conjunction rule. Mary is running if and only if Linda is reading a book can be inferred via the biconditional introduction rule. Linda is reading a book if and only if Mary is running can be inferred via the biconditional introduction rule. If Mary goes running, then it is snowing can be inferred via the biconditional elimination rule. If it snows, then Mary is running can be inferred via the biconditional elimination rule. Mary is not running can be inferred via the biconditional elimination rule.