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 rains, then Elisabeth is a politician. If it rains, then Elisabeth is reading a book. If Elisabeth reads a book, then Elisabeth is a politician. If Elisabeth were a politician, then it is raining.
If it rains, then Elisabeth is a politician can be inferred via the transitivity rule. If Elisabeth reads a book, then it is raining can be inferred via the transitivity rule. If Elisabeth were a politician, then Elisabeth is reading a book can be inferred via the transitivity rule. It is raining if and only if Elisabeth is a politician can be inferred via the biconditional introduction rule. Elisabeth is a politician if and only if it is raining can be inferred via the biconditional introduction rule.