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, if x_5 reads a book, then x_5 is writing a letter. For all x_5, if x_5 were bored, then x_5 is writing a letter. There is at least one x_5 for which if x_5 climbs a mountain, then x_5 is reading a book. For all x_5, x_5 will climb a mountain.
There is at least one x_5 for which x_5 will read a book can be inferred via the existential modus ponens rule. There is at least one x_5 for which if x_5 climbs a mountain, then x_5 is writing a letter can be inferred via the existential transitivity rule.