A Visual Explanation for Computing Minimal Cover

In the algorithm of determining a minimal cover for a given set of functional dependencies, eliminating extraneous attributes of each functional dependency should be done before removing redundant functional dependencies. The deeper reasons for doing so is still not clear. According to some kind of isomorphic connection between logic algebra and the theory of functional dependencies computing a minimal cover is equivalent to simplifying a logic function. The process of simplifying a logic function by using Karnaugh map in logic algebra is clear and visual, so a clear and visual explanation for that of determining a minimal cover is obtained.