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_1, if x_1 sleeps, then x_1 is a mechanic. There is at least one x_1 for which x_1 is rich. For all x_1, x_1 will sleep.
For all x_1, x_1 is a mechanic can be inferred via the universal modus ponens rule. There is at least one x_1 for which x_1 is rich and x_1 will sleep can be inferred via the existential conjunction rule. There is at least one x_1 for which x_1 will sleep and x_1 is rich can be inferred via the existential conjunction rule.