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: There is at least one x_12 for which x_12 is an electrician or x_12 will not climb a mountain. For all x_12, x_12 will climb a mountain or x_12 will write a letter. For all x_12, if x_12 writes a letter, then x_12 is an electrician.
There is at least one x_12 for which if x_12 climbs a mountain, then x_12 is an electrician can be inferred via the existential rewriting rule.