double back-substitution

例句：

1. 1.In the double back-substitution method, we first identify the variables that are not affected by the input data.
   在双回溯替换方法中，我们首先识别出不受输入数据影响的变量。
2. 2.The double back-substitution method is particularly useful for dealing with large datasets where traditional methods may be inefficient.
   双回溯替换方法对于处理大型数据集特别有用，因为传统方法可能效率不高。
3. 3. The double back-substitution technique can help us to optimize our code and improve its performance.
   双回溯替换技术可以帮助我们优化代码并提高其性能。