Originally posted by: D459_Parmanand_Sinha

I am trying to use boolean decision variables in logical constraints:

forall(u in Landu) forall(v in Landv)
ct:
(x[u][v][1]==1) => (xu-1[v][1]+xu+1[v][1]+x[u]v-1[1]+x[u]v+1[1]>=1);

It shows error "Index out of bound for array "x": 0." and OPL cannot extract expression.
How can I write these constraints properly?

Thnaks
#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi,

your issue is not about logical constraints but about indexing. You try to use cells that are not in the array.

The following model works fine:

{int} Landu={1,2};
{int} Landv={1,2};
 
{int} LanduB=Landu union {0,3};
{int} LandvB=Landv union {0,3};
 
dvar int x[LanduB][LandvB][1..1];
 
subject to
{
forall(u in Landu) forall(v in Landv)
ct:
(x[u][v][1]==1) => 
(x[u-1][v][1]+x[u+1][v][1]+x[u][v-1][1]+x[u][v+1][1]>=1);
}

regards
#DecisionOptimization
#OPLusingCPLEXOptimizer