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 it is overcast, then Richard is not playing a game. It is cold or Richard is playing a game. It is not snowing. It is cold if and only if it is snowing.
If it is cold, then it is snowing can be inferred via the biconditional elimination rule. If it snows, then it is cold can be inferred via the biconditional elimination rule. It is not cold can be inferred via the biconditional elimination rule.