discrete perpetuity model

例句：

1. 1. The discrete perpetuity model is a mathematical framework for analyzing the long-term impact of environmental policies.
   离散的持续模型是一种数学框架，用于分析环境政策长期影响。
2. 2. In this model, the decision-making process is divided into several stages, each with its own set of criteria and constraints.
   在这个模型中，决策过程被分成几个阶段，每个阶段都有其自己的一套标准和约束条件。
3. 3. The model's effectiveness in predicting future trends was tested against historical data, showing that it could accurately forecasteconomic growth and fluctuations.
   该模型在预测未来趋势方面的有效性通过与历史数据的对比测试得到了验证，显示出它可以准确预测经济增长和波动。