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_10 for which x_10 will climb a mountain or x_10 is not an office clerk. For all x_10, if x_10 climbs a mountain, then x_10 is an office clerk. For all x_10, if x_10 climbs a mountain, then x_10 is a carpenter.
There is at least one x_10 for which if x_10 were an office clerk, then x_10 is climbing a mountain can be inferred via the existential rewriting rule.