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_12, if x_12 were a server, then x_12 is writing a letter. If Patricia were a server, then Linda is rich. For all x_12, x_12 is a server or x_12 will not write a letter.
For all x_12, if x_12 writes a letter, then x_12 is a server can be inferred via the universal rewriting rule.