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 Karen plays squash, then Barbara is cooking. If Barbara cooks, then Karen is playing squash. Karen is playing squash or Barbara is a politician. If Barbara were a politician, then Barbara is cooking.
If Barbara were a politician, then Karen is playing squash can be inferred via the transitivity rule. Barbara is cooking can be inferred via the disjunction elimination rule. Karen is playing squash if and only if Barbara is cooking can be inferred via the biconditional introduction rule. Barbara is cooking if and only if Karen is playing squash can be inferred via the biconditional introduction rule.