We present a new approach to the logical design of fourth normal form relations. Our approach possesses the features which are desired as capabilities of automatic tools. The main features of the proposed approach are as follows.
(1) Introduction of single attribute right hand side
(2) Exention of the concept of independent relations
(3) Semantic analysis
(4) Adoption of dependency matrix
The underlying viewpoint of functional relationships of the approach are different from the Fagin``s fourth normal form in that we distinguish functional dependency and multivalued dependency in terms of cardinality. An algorithm for an automatic generation of fourth normal forms is provided.