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 not raining. It is raining if and only if Robert is drinking water. If it is windy, then Robert is drinking water. It is snowing if and only if it is windy.
If it rains, then Robert is drinking water can be inferred via the biconditional elimination rule. If it snows, then it is windy can be inferred via the biconditional elimination rule. If Robert drinks water, then it is raining can be inferred via the biconditional elimination rule. If it is windy, then it is snowing can be inferred via the biconditional elimination rule. Robert is not drinking water can be inferred via the biconditional elimination rule.