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 it is windy, then David is working. Susan is not a politician. If Susan were a janitor, then it is windy. David is working if and only if Susan is a politician. If David works, then Susan is a janitor.
If it is windy, then Susan is a janitor can be inferred via the transitivity rule. If Susan were a janitor, then David is working can be inferred via the transitivity rule. If David works, then it is windy can be inferred via the transitivity rule. If David works, then Susan is a politician can be inferred via the biconditional elimination rule. If Susan were a politician, then David is working can be inferred via the biconditional elimination rule. David is not working can be inferred via the biconditional elimination rule.