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_12, x_12 will drink water if and only if x_12 will make tea. For all x_12, x_12 is a mechanic. For all x_12, x_12 will make tea or x_12 is a soldier. For all x_12, if x_12 were a soldier, then x_12 is playing a game. For all x_12, x_12 will not drink water.
For all x_12, if x_12 drinks water, then x_12 is making tea can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 makes tea, then x_12 is drinking water can be inferred via the universal biconditional elimination rule. For all x_12, x_12 will not make tea can be inferred via the universal biconditional elimination rule.