[eclipse-clp-users] issues with ic and simplification

From: Ulrich Scholz <Ulrich.Scholz_at_eml-d.villa-bosch.de>
Date: Mon, 19 Jan 2009 13:39:01 +0100
Dear all,

it seems that ic on the order and kind of the constraints that are used.

For example, why does ECLiPSe find the correct answer with "[eclipse 5]" but
delays with "[eclipse 7]"?



[eclipse 3]: integers([X]), ic:(X #>X).

No (0.00s cpu)
[eclipse 4]: integers([X,Y]), X #= Y, X #>Y.

X = X{-1.0Inf .. 1.0Inf}
Y = X{-1.0Inf .. 1.0Inf}


Delayed goals:
        -(X{-1.0Inf .. 1.0Inf}) + X #> 0
Yes (0.00s cpu)
[eclipse 5]: [X,Y] :: [0,100], X #= Y, X #> Y.

No (0.00s cpu)
[eclipse 7]: integers([X,Y]), X#>1, Y#>1, X#<100, Y#<100, X#=Y, X#>Y.

X = X{2 .. 98}
Y = X{2 .. 98}


Delayed goals:
        -(X{2 .. 98}) + X #> 0
Yes (0.00s cpu)



To get failure fast, I could use labeling as follows.  Is there a better way?

testVariables(Vars) :-
    setval(test, 0),

    (
        labeling(Vars),
        setval(test, 1),
        fail
    ;
        true
    ),

    getval(test, 1).



Thanks,

Ulrich
Received on Mon Jan 19 2009 - 12:39:19 CET

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