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_8, if x_8 were an office clerk, then x_8 is not sleeping. There is at least one x_8 for which x_8 is curious if and only if x_8 is an office clerk. For all x_8, x_8 will sleep.
For all x_8, x_8 is not an office clerk can be inferred via the universal modus tollens rule. There is at least one x_8 for which if x_8 were curious, then x_8 is an office clerk can be inferred via the existential biconditional elimination rule. There is at least one x_8 for which if x_8 were an office clerk, then x_8 is curious can be inferred via the existential biconditional elimination rule.