The advanced techniques for formal presentation of fuzzy rule bases introduced in the previous chapter are essential to the complexity management in fuzzy systems. These techniques not only compress the information contained by the fuzzy system but they also facilitate the identification of the properties of the fuzzy rule base. However, sometimes we may want to change the properties of a fuzzy rule base by manipulating its formal presentation appropriately. For example, we may want to make an inconsistent rule base consistent or an incomplete rule base complete.