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: For all x_14, x_14 is a soldier if and only if x_14 will read a book. William is reading a book if and only if William is a soldier.
If William reads a book, then William is a soldier can be inferred via the biconditional elimination rule. If William were a soldier, then William is reading a book can be inferred via the biconditional elimination rule. For all x_14, if x_14 were a soldier, then x_14 is reading a book can be inferred via the universal biconditional elimination rule. For all x_14, if x_14 reads a book, then x_14 is a soldier can be inferred via the universal biconditional elimination rule.