x1 pertains to the numerically higher/greater/superior side of x2 under order relation/judging aspect x3.
For example, a Gaussian has two tails; the tail with the greater numbers (which is traditionally/conventionally plotted on the right side of a horizontally oriented scale) is kamyzmakezra'a. For another example, suprema and infima are the bounds on a set; suprema are bounds from (so-called) above - in other words, from the numerically greater side of the set in question. This word is used for every reference of saying "above", "upper", or "right" in the context of ordered numbers, since these terms are culturally-dependent. See also: kamymeckezra'a.