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_5, x_5 is a lawyer. For all x_5, if x_5 writes a letter, then x_5 is sad. For all x_5, if x_5 were a lawyer, then x_5 is cooking. For all x_5, x_5 will work or x_5 will write a letter. For all x_5, if x_5 works, then x_5 is sad.
For all x_5, x_5 will cook can be inferred via the universal modus ponens rule. For all x_5, x_5 is sad can be inferred via the universal disjunction elimination rule.