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 plays a game, then it is windy. If it is windy, then Mary is playing a game. Mary is playing a game or it is not windy.
If it is windy, then Mary is playing a game can be inferred via the rewriting rule. Mary is playing a game if and only if it is windy can be inferred via the biconditional introduction rule. It is windy if and only if Mary is playing a game can be inferred via the biconditional introduction rule.