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*Definition:* *relation*

Ris a relation betweenS_{0}, ...,S_{n-1}: <=>

RsubsetS_{0}x ... xS_{n-1}.

Ris ann-ary relation : <=>

existsS_0, ...,S_n-1:Ris a relation betweenS_0, ...,S_n-1;

Ris ann-ary relation onS: <=>

RsubsetSx ... xS(cartesian product ofninstances ofS).

Ris a relation onS: <=>Ris a 2-ary (binary) relation onS.

*Set of tuples of related values*.

Author: Wolfgang Schreiner

Last Modification: October 14, 1999