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_7, if x_7 were happy, then x_7 is drinking water. For all x_7, x_7 will play squash. For all x_7, if x_7 were a doctor, then x_7 is drinking water. For all x_7, x_7 is happy or x_7 is a doctor.
For all x_7, x_7 will drink water can be inferred via the universal disjunction elimination rule.