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 William were not a scientist, then it is cold. Charles is curious. William is a scientist if and only if it is raining. It is not raining.
Charles is curious and it is not raining can be inferred via the conjunction rule. It is not raining and Charles is curious can be inferred via the conjunction rule. If William were a scientist, then it is raining can be inferred via the biconditional elimination rule. If it rains, then William is a scientist can be inferred via the biconditional elimination rule. William is not a scientist can be inferred via the biconditional elimination rule.