Applying T to every value function at once

Each dot is one value function v = (v(1), v(2)) of a two-state MDP. One press applies the Bellman optimality operator T to all of them. The dashed box is the smallest square holding the cloud: its side is the cloud's diameter in the sup norm.

Value-function plane, iteration k = 0

u w ★ fixed point v* faint dots: previous iterate

Distances after k applications (log scale)

cloud diameter ‖u − w‖∞ γk × start
Cloud diameter, now / start1.000
γk1.000
‖u − w‖∞–
‖u − v*‖∞–