[eclipse-clp-users] Eclipse library IC question on reading the intervals

Hi,


I am using eclipse 7.0 #42 for linux 64 bits, and after loading (in the 
interpreter) the IC library the answer to the following query appears 
"erroneous" to me.

[eclipse 2]: [E1,E2,N1] $:: -1..1, X $= 4 + E1 + E2 + N1, X $= -E1 + 3*E2.

E1 = E1{-1.0 .. 0.5000000116152874}
E2 = E2{0.49999998838471316 .. 1.0}
N1 = N1{-1.0 .. 0.5000000116152874}
X = X{2.4999999651541396 .. 4.0}


Delayed goals:...

It appears to me that the interval for E1 should be -1..-0.5 and that of 
N1 should be -1..0.

We can, roughly, see that this is the case for E1 when we 'narrow' the 
domain of E1 as follows.

[eclipse 3]: E1 $:: -0.4..0.5, [E2,N1] $:: -1..1, X $= 4 + E1 + E2 + N1, 
X $= -E1 + 3*E2.

No (0.00s cpu)

What am I missing in the reading of the displayed intervals?

Is there an heuristic/method to lead the constraint solver to a tighter 
answer, in my example?

Kind regards,

Julio