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_6, if x_6 reads a book, then x_6 is a sailor. For all x_6, x_6 is not a sailor. Joseph is reading a book or Elisabeth is bored.
For all x_6, x_6 will not read a book can be inferred via the universal modus tollens rule.