Parsing problem

[Prasad Nayak]

Hello,
   I have compiled the Snacc-1.3 parser. When i run the snacc compiler, it
givens me error for nested messages. 

for exmaple,
   example ::= SEQUENCE
      { 
           something CHOICE
                 {  ..........
                .....
             }
       }

I have a dought whether the Snacc-1.3 supports this ???  Does Snacc supports
X.680 and higher versions ????

Thanks in advance,
Prasad