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 not raining. It is overcast if and only if James is excited. It is raining if and only if it is overcast.
If it is overcast, then James is excited can be inferred via the biconditional elimination rule. If it rains, then it is overcast can be inferred via the biconditional elimination rule. If James were excited, then it is overcast can be inferred via the biconditional elimination rule. If it is overcast, then it is raining can be inferred via the biconditional elimination rule. It is not overcast can be inferred via the biconditional elimination rule.