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 playing squash or Charles is cooking. If Karen plays squash, then it is snowing. Charles is cooking if and only if it is snowing.
If Charles cooks, then it is snowing can be inferred via the biconditional elimination rule. If it snows, then Charles is cooking can be inferred via the biconditional elimination rule.