Figure 3
From: A novel asynchronous access method with binary interfaces

Sample spatial exclusion masks ( c ). The top mask represents the fundamental knowledge implied by the principle of asynchronous access. Because of its maximum value (c = c[n-1]) = 1, the element c[n-1]cannot be chosen when selecting a new device outcome c[n]. The bottom mask represents the assumption that outcomes similar to c[n-1]should also be excluded from the selection of c[n].