Tomás Brázdil Václav Brozek Kousha Etessami Antonín Kucera Dominik Wojtczak One-Counter Markov Decision Processes http://arxiv.org/abs/0904.2511 2009 CoRR abs/0904.2511 db/journals/corr/corr0904.html#abs-0904-2511 informal publication