【求助】tag_t

leechongqing

UF_ASSEM_ask_work_occurrence
  
Returns the work occurrence of the work part.
  
See Also
  
Return
Returns the tag of the work occurrence. Returns a
NULL_TAG if there is no current work part, or if
the work part occurrence is the displayed part.
  
extern tag_t UF_ASSEM_ask_work_occurrence ( );
  
Environment
Internal and External
  
UF_ASSEM_ask_work_part
  
Returns the part tag of the current work part.
  
See Also
  
Return
Returns the tag of the current work part, else
returns a NULL_TAG if there is no current work
part.
  
extern tag_t UF_ASSEM_ask_work_part ( );
  
Environment
Internal and External
  
这两个函数到底有什么区别阿？
我不明白occurrence 和work part 的区别，还有，这个tag_t到底怎么理解阿？