Re: SgFuncRefExp

>> Ther is no SgFuncRefExp in the sage manual,

Hmm, looks like a problem with the manual. There definitely is 

an SgFunctionRefExp class in Sage++ (note the different spelling!).  
When in doubt, look in the libSage++.h file. The manual is not quite  
up to date. Updating it is on my "to do" list but, admittedly, it has  
a rather low priority.