Minizinc似乎生成无效的FZ代码。

Question

下面是我的模型：

constraint forall(d in Day, s in Student)
(
  let {
    %groups in day
    array[int] of var opt Group: gid = [g | g in assignment[s] where group_day[g] == d];
    %groups starts in day
    array[int] of var opt Time: gsid = [group_start[g] | g in gid];
    %groups ends in day
    array[int] of var opt Time: geid = [group_end[g] | g in gid];
    %groups durations in day
    array[int] of var opt Time: gdid = [group_duration[g] | g in gid];
    var opt Time: min_start = min(gsid);
    var opt Time: max_end = max(geid);
    var opt Time: sum_dur = sum(gdid);
    var opt int: time = ((max_end - min_start) - sum_dur);
  } in
  wasted_time_units[d,s] = deopt(time)
);

我一直试图通过从模型中删除opt数据类型，通过取消整个gid来使其正常工作，但这导致了model inconsistency detected错误。修复和取消gid数组是有效的，但是assignment是一个变量，因此产生无效的输出。最后，我到达了上面显示的模型，它通过了类型检查，但是现在我得到了一个神秘的错误：

Error: Unknown character in line no. 1914
Error: Unknown character in line no. 1914
Error: Unknown character in line no. 1914
Error: syntax error, unexpected '(', expecting FZ_ID in line no. 1914

下面我附加了FlatZinc输出(行号放在方括号中)：

[1913] constraint int_lin_eq([1,1,1,-1],[X_INTRODUCED_894_,X_INTRODUCED_908_,X_INTRODUCED_922_,X_INTRODUCED_955_],0):: defines_var(X_INTRODUCED_955_);
[1914] constraint '-'(X_INTRODUCED_954_,X_INTRODUCED_952_,X_INTRODUCED_956_):: defines_var(X_INTRODUCED_956_);
[1915] constraint '-'(X_INTRODUCED_956_,X_INTRODUCED_955_,X_INTRODUCED_957_):: defines_var(X_INTRODUCED_957_);
[1916] constraint int_ne_reif(X_INTRODUCED_963_,0,X_INTRODUCED_962_):: defines_var(X_INTRODUCED_962_);

这个错误意味着什么，我如何避免它？看起来minizinc正在生成无效的FZ代码。

Answer 1

这个问题是通过修补小型产品来解决的。

在这里处理了问题：https://github.com/MiniZinc/libminizinc/issues/588

在编译开发部门之后，这个问题就消失了！