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: Susan is not drinking water. Charles is an artist if and only if Richard is playing a game. Richard is not playing a game. If it rains, then Susan is drinking water.
It is not raining can be inferred via the modus tollens rule. Susan is not drinking water and Richard is not playing a game can be inferred via the conjunction rule. Richard is not playing a game and Susan is not drinking water can be inferred via the conjunction rule. If Charles were an artist, then Richard is playing a game can be inferred via the biconditional elimination rule. If Richard plays a game, then Charles is an artist can be inferred via the biconditional elimination rule. Charles is not an artist can be inferred via the biconditional elimination rule.