Horizontal Rectangle

A set of coordinates R is an horizontal rectangle if there exist a coordinate (x, y) and numbers w and h such that all coordinates (a, b) with x ⩽ a ⩽ x+w and y ⩽ b ⩽ y+h are part of R.

R is then said to have corner (x, y), width w, and height h.

Note that the rectangle is "horizontal" in the sense that its sides align with the axis of the coordinate system.