我不知道如何在 CPLEX 中编写 (i ∈ V^a∪ V^s) 以下条件？答案

【问题标题】：I don't know how can I write (i ∈ V^a∪ V^s) the below conditions in CPLEX?我不知道如何在 CPLEX 中编写 (i ∈ V^a∪ V^s) 以下条件？
【发布时间】：2021-10-03 16:36:50
【问题描述】：

∑((i,j ∈A_2) )(x_ij)+∑_((i,j,k)∈A_3)(y_ijk) = 1, i ∈ V^a∪ V^s

V^a和V^s的交集不知道怎么写，对吗？

{int} Arr_node;
{int} Loco_start;
{int} Exp1= Arr_node inter Loco_start;
 
Forall(i in Exp1)(sum(<i,j> in A2)x[<i,j>]) + (sum(<i,j,k> in A3)y[<i,j,k>]) == 1;

【问题讨论】：

标签： cplex forall

【解决方案1】：

你可以使用 inter 或 &&

见

{string} cities={"A","B","C"};

{string} departures={"A","B"};
{string} arrivals={"B","C"};

dvar boolean x[cities];

{string} bothdepandarr=departures inter arrivals;

minimize sum(c in cities) x[c];

subject to
{
  forall(c in bothdepandarr) x[c]==1;
}

或

{string} cities={"A","B","C"};

{string} departures={"A","B"};
{string} arrivals={"B","C"};

dvar boolean x[cities];



minimize sum(c in cities) x[c];

subject to
{
  forall(c in departures inter arrivals) x[c]==1;
}

或

{string} cities={"A","B","C"};

{string} departures={"A","B"};
{string} arrivals={"B","C"};

dvar boolean x[cities];



minimize sum(c in cities) x[c];

subject to
{
  forall(c in cities : c in departures && c in arrivals) x[c]==1;
}

【讨论】：