A pony may not harm a human being, or by inaction allow a human to come to harm.
A pony must be able to preserve itself from harm as long as doing so does not conflict with the above rule.
A pony must be able to follow orders from a human at any given time, provided these orders do not conflict with the above two rules.
Additionally, a pony may not be allowed to harm humanity, or by inaction allow humanity to come to harm.