Data refinement is hard to deal with in a refinement tool compared with ordinary algorithmic refinement, since data refinement usually has to be done on a large programcomponent at once.
由于数据精化需要针对更大的程序块，所以，它比一般的算法精化更加复杂。
2
Begin by modifying the program to compile only the component we need.
先修改程序，让它只编译我们需要的组件。
3
But you should break up the program into component parts, and use comments to fill in the gaps.