It’s Hard to Color Antirectangles
Andy Boucher · SIAM Journal on Algebraic and Discrete Methods · 1984
The maximum number of elements in an antirectangle of a convex board equals the minimum number of rectangles it takes to cover that board. It is shown here that the dual of this theorem, that the minimum number of antirectangles needed to cover a convex board equals the maximum size of any rectangle of the board, is not generally true.