obstacle problems的用法和樣例：
例句
- He is researching the reading problems of young school children.
他正在研究年輕學生的閱讀障礙問題。 - Moreover, when the matrix involved in the two-sided obstacle problem is a symmetric and nondegenerate matrix, the sequence converges to a solution of the problem.
並且，當矩陣為非退化對稱矩陣時，該序列收斂到雙邊障礙問題的解。
