[gecode-users] Simple Reified relation

[Sameh El-Ansary]

 Hi,
I am trying to do something very simple in Gecode with reified constraints.
I would like to do the follwoing:
- x ranges from 4 to 6
- b is a boolean variable
- (x=:4) reified in  b
- When I assign x to 5, I expect b to be equal to 0, but b still ranges from
0..1 !!

i.e. I am trying to do what I would write in Oz as:
declare
X B
X :: 4#6
B :: 0#1
(X =:4)=B
X=:5
{Show [X B]}
This shows: [5 0]

I wrote that in Gecode by using unmanaged c++ in visual studio 2005 with the
windows binaries provided on the Gecode website as follows:

//--------------------------
class Wires : public Space {
public:
 Wires(){
  IntVar x(this,4,6);
  BoolVar b(this,0,1);
  rel(this,x,IRT_EQ,4,b);
  rel(this,x,IRT_EQ,5);
        cout << "x="<< x << " b= " << b << "\n";
 }
 Wires(bool share, Wires& e) : Space(share,e) {}
 virtual Space*  copy(bool share)
 { return new Wires(share,*this);
 }
};
 //--------------------------
This outputs:
x=5 b= [0..1]
I expected it to be
 x=5 b= 0

What am I missing here?

I also believe there is a small typo in the documentation on relations
void  Gecode::rel (Space *home, IntVar x, IntRelType r, int c, BoolVar b,
IntConLevel icl=ICL_DEF)
    Post propagator for .x  ~_r  c
I think it was meant to be
    Post propagator for .(x  ~_r  c)  <=> b
Or there is something I am really not getting in reifying relations!!

Sameh
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