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, x is a soldier if and only if x will drink water. For all x, x will not drink water. There is at least one x for which x will read a book if and only if x is a soldier.
For all x, if x were a soldier, then x is drinking water can be inferred via the universal biconditional elimination rule. There is at least one x for which if x reads a book, then x is a soldier can be inferred via the existential biconditional elimination rule. For all x, if x drinks water, then x is a soldier can be inferred via the universal biconditional elimination rule. There is at least one x for which if x were a soldier, then x is reading a book can be inferred via the existential biconditional elimination rule. For all x, x is not a soldier can be inferred via the universal biconditional elimination rule.