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, x_5 will not climb a mountain or x_5 will sleep. For all x_5, x_5 will not work or x_5 will climb a mountain. There is at least one x_5 for which x_5 will work or x_5 is an office clerk. For all x_5, x_5 is not an office clerk or x_5 will drink water.
There is at least one x_5 for which x_5 is an office clerk or x_5 will climb a mountain can be inferred via the existential resolution rule.