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: Karen is not working. It is snowing if and only if Karen is working. It is overcast if and only if it is not snowing.
If it snows, then Karen is working can be inferred via the biconditional elimination rule. If it is overcast, then it is not snowing can be inferred via the biconditional elimination rule. If Karen works, then it is snowing can be inferred via the biconditional elimination rule. If it doesn't snow, then it is overcast can be inferred via the biconditional elimination rule. It is not snowing can be inferred via the biconditional elimination rule.