cairo:region-subtract-rectangle (region x y width height)

region -- a cairo:region-t instance
x -- an integer for the x coordinate
y -- an integer for the y coordinate
width -- an integer for the width of the rectangle
height -- an integer for the height of the rectangle

The passed in cairo:region-t instance with the result or nil if an error occured.

Subtracts rectangle from region and places the result in region.