convenience function的用法和樣例：
例句
- A tabulation of a function of two variables is cumbersome, but possible.
二元函數的列表法是不方便的，然而是可能的。 - The utility cost function is considered, which includes the increase of trip expense and trip time, reduction of comfort and decrease of convenience during the transfer.
該效用損失函數充分考慮了居民換乘導致出行時間和費用的增加以及舒適性和方便性的損失。
