bool valid(const tFSM& fsm){

size_t mx = fsm.size();
vector<tFSM::tState> invalst;

    for (tFSM::tState curr = 0; curr < mx; ++curr)
    {
        set<tFSM::tState> st;
        tFSM::tTransMap::const_iterator it;
    if (fsm.table[curr].size() == 0 && fsm.finals.count(curr) == 0)
    {
        invalst.push_back(curr);
        continue;
    }

    for (it = fsm.table[curr].cbegin(); it != fsm.table[curr].cend(); ++it)
        st.insert(it->second);

    if (st.size() == 1)
    {
        set<tFSM::tState>::const_iterator stit = st.cbegin();
            if (*stit == curr && fsm.finals.count(curr) == 0)
                invalst.push_back(curr);
    }
    }

    if (invalst.size() > 0)
    {
        ostringstream tmp;
        int wstate = 0;
    for(vector<tFSM::tState>::const_iterator i =  invalst.cbegin(); i != invalst.cend(); ++i)
    {
        tmp << "State " << setw(2) << int(*i) <<
        tmp << " is deadlocked. ";
                        wstate++;
                        if (wstate%2 == 0)
                        {
                                tmp << endl << ' ';
                        }
    }
    errmessage = tmp.str();
    errcode = 5;
    return false;
}

  errcode=0;
  return true;
}