[GiNaC-list] list input

Hi. I'm trying to use list as input. List as output prints {expr1,expr2,..}, list.nops() is varying. When I write list as: parser reader; somelist=reader(cin); where input to cin: {expr1,expr2,..} at the end shift-D It returns somelist={expr1,expr2,..}, somelist.nops()=1. When accessing the 2nd and higher element of list, program gets segmentation fault.