DIVIDEBY in PostgreSQL

Hi

Would you mind to tell me how the DIVIDEBY operator could be
defined (the way Codd E.F [1] or Date C.J [2] define it) in
PostgreSQL ?

Using PostgreSQL 7.1.2

Thanks in advance.

1 Codd E.F. Relational Completeness of Data Base Sublanguages
2 Date C.J. An Introduction to Database Systmes 6th ed.

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Vladimir Zolotych gsmith@eurocom.od.ua