Define Rules for Reducing Karnaugh Maps?

The rules for reducing Karnaugh Maps (k- maps) are as follows:

• All of the 1's in the Karnaugh Map are called as minterms.
• The 1's can be condensed in the groups of 2, 4 & 8.
• Minterms that are next to each other vertically or horizontally can be grouped together.
• Minterms that have been grouped in the Karnaugh Map can be reduced to the boolean terms that are common with all the terms in the group.
• The Minterms that cannot be grouped together cannot be reduced.
• You may use the minterm for grouping more than once.