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_10, if x_10 drinks water, then x_10 is happy. For all x_10, if x_10 reads a book, then x_10 is playing squash. For all x_10, if x_10 were happy, then x_10 is drinking water. For all x_10, x_10 will read a book. For all x_10, if x_10 plays squash, then x_10 is drinking water.
For all x_10, x_10 will play squash can be inferred via the universal modus ponens rule. For all x_10, if x_10 reads a book, then x_10 is drinking water can be inferred via the universal transitivity rule. For all x_10, if x_10 plays squash, then x_10 is happy can be inferred via the universal transitivity rule. For all x_10, x_10 will drink water if and only if x_10 is happy can be inferred via the universal biconditional introduction rule. For all x_10, x_10 is happy if and only if x_10 will drink water can be inferred via the universal biconditional introduction rule.