[eclipse-clp-users] Defining domains for IntegerSet variables

Hie, 

We would like to use IntegerSet variables whose initial domains
are not a single interval, but a UNION of intervals. 

Example : X1 :: [1,2]..[1,2,5,7] op [2]..[2,4,7] op [3,6]..[3,4,6,7] 

where op represents the union of 2 Sets of IntegerSets. 

Is there a simple way to state this in ECLiPSe, since union
is defined for IntegerSets but not for Sets of IntegerSets ?
(and we don't want to have to enumerate each of the intervals) 

Thanks for your help, 

Best regards, 

Patrice Boizumault