Fig. 6. Accessibility of specific addition patterns in the cage windows for a second addition on 2⊂1 (top, first addend purple) and a third addition on 3-e⊂1 (middle left, e-addends in red), 3-t4⊂1 (middle right, t4-addends in blue), 3-t3⊂1 (bottom left, t3-addends in green) and 3-t2⊂1 (bottom right, t2-addends in yellow).
