title: Difference about getIIS and refineConflict
body: <p>I'm using cplex to solve a linear programming problem. Since the time of invoking getIIS is long when the size of the problem is large, I try to use refineConflict method
  to find the minimal conflict instead. But the result of invoking getIIS and refineConflict is very different. Below is the result of a unsatisfiable linear programming problem.</p>
  
  <p>The result of invoking getIIS:</p>
  
  <pre><code>IloRange 3_4 : 0.0 &lt;= (-1.0*water_t_4 + 1.0*water_v_1_4) &lt;= infinity
  IloRange 3_4 : 5.0 &lt;= (2.0*water_t_4 + 1.0*water_v_2_4) &lt;= infinity
  IloRange 4_5 : 0.0 &lt;= (-1.0*water_v_2_4 - 1.0*water_t_5 + 1.0*water_v_2_5) &lt;= infinity
  IloRange 4_5 : 2.0 &lt;= (1.0*water_v_1_4) &lt;= 2.0
  IloRange 5_6 : 0.0 &lt;= (1.0*water_v_2_5) &lt;= 0.0
  </code></pre>
  
  <p>The result of invoking refineConflict(the first parameter is the whole linear constraints and the second is a array in which the member is set to 1).</p>
  
  <pre><code>Possible : IloRange 4_5 : 2.0 &lt;= (1.0*water_v_1_4) &lt;= 2.0
  Possible : IloRange 5_6 : 0.0 &lt;= (1.0*water_v_2_5) &lt;= 0.0
  </code></pre>
  
  <p>I feel confused about the results given by the two methods. 
  Here is my code and the version my cplex is cplex_studio125.win-x86-64:</p>
  
  <pre><code>cplex=new IloCplex();
  cplex.setParam(IloCplex.IntParam.Threads,1);
  cplex.setParam(IloCplex.IntParam.RootAlg, IloCplex.Algorithm.Concurrent);
  cplex.addRangel()...
  if(!cplex.solve){
     IloConstraint[] arr is the whole linear constraints 
      double prefs[] = new double[arr.length];
      Arrays.fill(prefs, 1);
      if(cplex.refineConflict(arr, prefs)){               
        ConflictStatus[] conflicts = cplex.getConflict(arr);
        for (int i1 = 0; i1 &lt; conflicts.length;i1++ ){                 
          if(conflicts[i1]== ConflictStatus.Member)
             System.out.println(" Proved : " + arr[i1]);
          else if (conflicts[i1]==ConflictStatus.PossibleMember)
             System.out.println(" Possible : " + arr[i1]);
        }
      }
   }
  </code></pre>
  
  <p>Thanks for your help.</p>