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 raining if and only if it is overcast. Charles is working if and only if it is overcast. It is not snowing. It is raining if and only if it is snowing.
If it rains, then it is overcast can be inferred via the biconditional elimination rule. If Charles works, then it is overcast can be inferred via the biconditional elimination rule. If it rains, then it is snowing can be inferred via the biconditional elimination rule. If it is overcast, then it is raining can be inferred via the biconditional elimination rule. If it is overcast, then Charles is working can be inferred via the biconditional elimination rule. If it snows, then it is raining can be inferred via the biconditional elimination rule. It is not raining can be inferred via the biconditional elimination rule.