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: There is at least one x_7 for which if x_7 were a politician, then x_7 is sad. For all x_7, if x_7 were sad, then x_7 is not writing a letter. For all x_7, x_7 will write a letter and x_7 is poor.
For all x_7, x_7 will write a letter can be inferred via the universal simplification rule. For all x_7, x_7 is poor can be inferred via the universal simplification rule.