Group 1s in each of the Karnaugh map in Figure 3.6.7.
According to the rules of grouping 1s, the result of grouping 1s is shown in Figure 3.6.8.
For each Karnaugh map, the number of the groups is minimized and the size of the groups is maximized.
Notice that Figures 3.6.8 (a) and (b) have the same Karnaugh map but different grouping results.
These mean that there may be more than one way to group the 1s for a Karnaugh map.