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*Definition: domain and range of a binary relation R*

- The domain of
`R`is the set of first components of the tuples in`R`:domain(

`R`) := {`r`_{0}:`r`in`R`}. - The range of
`R`is the set of second components of the tuples in`R`:range(

`R`) := {`r`_{1}:`r`in`R`}.

forallx:xin domain(R) <=>existsy: <x,y> inR,forally:yin range(R) <=>existsx: <x,y> inR.

Author: Wolfgang Schreiner

Last Modification: October 14, 1999