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 were a writer, then x_1 is working. There is at least one x_1 for which x_1 is a writer. For all x_1, if x_1 were a police officer, then x_1 is working.
There is at least one x_1 for which x_1 will work can be inferred via the existential modus ponens rule.