relational algebras, logic, and functional programming
Relational algebras as developed by Codd and his followers are extended by noting an equivalence with functional languages. This leads to higher order relations, recursive definitions of relations, and the use of higher order relations as recursive data structures. This equivalence on the one hand enables the technology of databases to be used within the context of applicative languages, and on the other hand removes the adhoc mechanisms used for higher order operations in relational databases. This leads from 4th to 5th generation data management, exploiting the mathematical foundations of functional languages and logic programming, and the technology of relational database.
relation algebra logic functional programming functional languages language order recursion definition use data structures technologies database context operability relational database generation data management logic program