NO
Nontermination proof succeeded
Found this recurrent set for cutpoint 6: 1 <= x_0 and 1 <= x_post and y_0 <= 0 and y_post <= 0 and y_0-x_0 <= -1 and x_0+y_0 <= 1 and 1 <= x_0+y_0 and x_post-x_0 <= 0 and x_0-x_post <= 0 and 2 <= x_post+x_0 and y_0-x_post <= -1 and x_post+y_0 <= 1 and 1 <= x_post+y_0 and y_post-x_post <= -1 and x_post+y_post <= 1 and 1 <= x_post+y_post and y_post-x_0 <= -1 and y_post+x_0 <= 1 and 1 <= y_post+x_0 and y_post-y_0 <= 0 and y_0-y_post <= 0 and y_post+y_0 <= 0 and 0 <= 0
Errors: