How to change value of dvar B as dvar A changes when dvar B depends on A

Question

Now I am facing with a problem about 'changing value of dvar B as dvar A changes when dvar B depends on A.'

There is a code that I write, simply.

int a = 3;
int e = 4;
int t = 6;
int h = 2;

range aRange = 1..a;
range eRange = 1..e;
range tRange = 1..t;
range hRange = 1..h;

int C[aRange][eRange] = [[2,5,8,7]
                         [3,6,8,1]
                         [8,7,1,0]];

int N[eRange][hRange] = [[8,6]
                         [4,1]
                         [9,7]
                         [5,4]];


dvar boolean A[aRange][eRange][tRange]; 
dvar int B[eRange][hRange][tRange] in 0..100;

maximize
sum(a in aRange, e in eRange, t in tRange, h in hRange) C[a][e] * A[a][e][t] * B[e][h][t];

subject to {

cons01 :
  forall(e in eRange, h in hRange, t in tRange) { 
      B[e][h][t] <= N[e][h]; }
}

In this case, I'd like to implement a condition that

'if x[a][e][t] = 0, then B[e][h][t] = B[e][h][t-1] + B[e][h][t-1]/N[e][h]. else x[a][e][t] = 1, B[e][h][t] = 0.'

How can I implement above condition into my code(constraints or subject function or use data script..?)

Answer 1

you can use logical constraints. You can for instance write:

forall(a in aRange,e in eRange,h in hRange,t in tRange:t!=1) 
(x[a][e][t] == 0) => (B[e][h][t] == B[e][h][t-1] + B[e][h][t-1]/N[e][h]);

in the "subject to" block