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_13, x_13 is a sailor or x_13 will cook. For all x_13, x_13 is not a writer or x_13 will go running. There is at least one x_13 for which if x_13 were a sailor, then x_13 is a writer. For all x_13, if x_13 cooks, then x_13 is happy. For all x_13, if x_13 were happy, then x_13 is a writer.
For all x_13, if x_13 cooks, then x_13 is a writer can be inferred via the universal transitivity rule.