NO
Nontermination proof succeeded
Found this recurrent set for cutpoint 5: t_0 == -10 and t_1 == -1 and t_2 == -2 and t_3 == -3 and t_4 == -4 and t_5 == -5 and t_6 == -6 and t_7 == -7 and t_8 == -8 and t_9 == -9 and t_post == -10 and x_0 == 0 and x_post == 0 and y_0 == 0
Errors: