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 Elisabeth reads a book, then Thomas is an office clerk. Thomas is an office clerk if and only if William is a soldier. Elisabeth is reading a book.
Thomas is an office clerk can be inferred via the modus ponens rule. If Thomas were an office clerk, then William is a soldier can be inferred via the biconditional elimination rule. If William were a soldier, then Thomas is an office clerk can be inferred via the biconditional elimination rule.