Originally posted by: GMB7_Wang_Kefeng
For arbitrary k in V, i in C and j in C, x[i][j][k]are blooean decision variables,
and I want to describe x[i][j][k] and x[j][i][k] can't be equal to 1 at the same
time. I know the expression x[i][j][k]*x[j][i][k]==0 can express the meaning above, but
it is nonlinear. So I transfer it into two linear inequalities as
0<=x[i][j][k]<=M*u and 0<=x[j][i][k]<=M*(1-u),
where M is a large positive number and u is blooean decision variable. I write the two
constraints in OPL language as:
forall(i in C,j in C,k in V)
0<=x[i][j][k]<=M*u[i];
0<=x[j][i][k]<=M*(1-u[i]);
But the system raises an error: decision variable (or expression)"u" are not
permitted.
What's wrong with my expression?
#DecisionOptimization#OPLusingCPLEXOptimizer