E1 : As Tuples are the lists except that they don't have few attributes compared to lists like append attribute.
So it likely to result in errors when a variable defined as tuple (bla,bla) is appendeded (append attribute called).
E2 : In this case ,a list as member in tuple can be used to append . This works fine because when a member of tuple is called as list then it acts as if like normal free list (free insense that not in tuple) and thus can be appended with elements.
