From: Wayne Mac Adams <waynemacadams_at_gmail.com>

Date: Wed, 22 Jul 2009 11:52:48 +0100

Date: Wed, 22 Jul 2009 11:52:48 +0100

Hi, Hopefully someone can help me with my problem, I have been advised to send an email to this mailing list. I have the following predictate prob_sum([],Sum,Sum). prob_sum([E | Tail], Sum,End):- prob_sum(Tail,Sum+E-Sum*E,End). It take a list of Variables and gets the probabilistic sum fo them. Somewhere else the sum is then constrained to be less than or equal to some other variable. However when the list has more than one element the domains of the variables in the list don't seem to propagate correctly. For example consider this query N::0.0..0.5, NA::0.0..1.0, NC::0.0..1.0, prob_sum([NA,NC],0,M),N1::0.0..1.0, eval(M) $=N1, N1 $=<N. It gives the result ?- N::0.0..0.5, NA::0.0..1.0, NC::0.0..1.0, prob_sum([NA,NC],0,M),N1::0.0..1.0, eval(M) $=N1, N1 $=<N. N = N{0.0 .. 0.5} NA = NA{0.0 .. 1.0} NC = NC{0.0 .. 1.0} M = 0 + NA{0.0 .. 1.0} - 0 * NA + NC{0.0 .. 1.0} - (0 + NA - 0 * NA) * NC N1 = N1{0.0 .. 0.5} There are 5 delayed goals. Yes (0.00s cpu) As you can see the domains for NA and NC remain from 0.0..1.0 when you would think they should be 0.0..0.5. Does anyone know how to solve this problem? It forms part of a larger problem in which I am getting an incorrect result because of the domains staying between 0.0..1.0. Any help is appreciated, Thanks, WayneReceived on Wed Jul 22 2009 - 10:52:56 CEST

*
This archive was generated by hypermail 2.2.0
: Thu Feb 02 2012 - 02:31:58 CET
*