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, if x reads a book, then x is drinking water. There is at least one x for which if x were a scientist, then x is reading a book. For all x, x is an astronaut or x will not drink water.
There is at least one x for which if x were a scientist, then x is drinking water can be inferred via the existential transitivity rule. For all x, if x drinks water, then x is an astronaut can be inferred via the universal rewriting rule.