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: Elisabeth is not drinking water. If Elisabeth drinks water, then James is an electrician. If James were an electrician, then Elisabeth is drinking water.
James is not an electrician can be inferred via the modus tollens rule. Elisabeth is drinking water if and only if James is an electrician can be inferred via the biconditional introduction rule. James is an electrician if and only if Elisabeth is drinking water can be inferred via the biconditional introduction rule.