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 overcast if and only if David is playing tennis. If Joseph plays a game, then it is overcast. David is playing tennis or it is not overcast.
If it is overcast, then David is playing tennis can be inferred via the rewriting rule. If it is overcast, then David is playing tennis can be inferred via the biconditional elimination rule. If David plays tennis, then it is overcast can be inferred via the biconditional elimination rule.