4. (30 points) Reinforcement Learning (RL) a) How do model-based learning methods in RL work? b) How do model-free learning methods in RL work? c) We talked about the following example for the model-based learning? Explain this example. Input Policy Observed Episodes (Training) Leamed Model Episode 1 Episode 2 T(3.0,8) B, east, C, -1 B, east, C.-1 TIB, east, C) = 1.00 C, east, D-1 C, east, D-1 TIC, east, D) = 0.75 TIC, east, A) +0.25 D, exit, X, +10 D, exit, X, +10 D A Episode 3 Episode 4 R(s, a, s') E, north, C, -1 E north, C, 1 R(Beast.C) - 1 C, east, D,-1 C, east, A, 1 RIC, east, D-1 RID. exit, x)+10 Assume: y = 1 D, exit X. +10 A exit, X.-10 No discounting U ku