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: Charles is playing a game if and only if Linda is a poet. It is snowing. If it snows, then Patricia is playing squash. Linda is not a poet.
Patricia is playing squash can be inferred via the modus ponens rule. It is snowing and Linda is not a poet can be inferred via the conjunction rule. Linda is not a poet and it is snowing can be inferred via the conjunction rule. If Charles plays a game, then Linda is a poet can be inferred via the biconditional elimination rule. If Linda were a poet, then Charles is playing a game can be inferred via the biconditional elimination rule. Charles is not playing a game can be inferred via the biconditional elimination rule.