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: Charles is bored if and only if Jennifer is playing squash. If Jennifer plays squash, then it is not windy. David is an electrician if and only if Charles is bored. It is windy.
Jennifer is not playing squash can be inferred via the modus tollens rule. If Charles were bored, then Jennifer is playing squash can be inferred via the biconditional elimination rule. If David were an electrician, then Charles is bored can be inferred via the biconditional elimination rule. If Jennifer plays squash, then Charles is bored can be inferred via the biconditional elimination rule. If Charles were bored, then David is an electrician can be inferred via the biconditional elimination rule.