How statement and proof provenance work
The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.
- Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
- AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
- AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.
These labels describe origin, not correctness: citations and verification chips remain separate evidence.
Model-based planning, Dyna, and model exploitation — Examples
1 · Prerequisites
- Conditional Distributions and Regular Conditional Probability
- Construction of the Natural Numbers
- Construction of the Real Numbers via Cauchy Sequences
- Construction of the Real Numbers via Dedekind Cuts
- Countability and Uncountability
- Finite Counting, Factorials and Binomial Coefficients
- Finite MDPs and Bellman operators
- Foundations of the Real Numbers for Analysis
- General-state MCMC ergodicity and mixing
- limsup, liminf, and Subsequential Limits
- Measurable Functions and Simple Approximation
- Measures and Their Basic Properties
- Model-based planning, Dyna, and model exploitation
- Monotone Sequences, Bolzano-Weierstrass, and Cauchy Completeness
- Order, Zorn's Lemma, and the Axiom of Choice
- Product Measures and the Fubini Tonelli Theorems
- Relations, Functions, and Quotients
- Roots, Rational Powers, and Classical Inequalities
- Sequences and Limits
- Sigma Algebras and Borel Sets
- Stationary Markov Chains and Ergodic Limits
- Suprema and Infima
- The Lebesgue Integral and the Convergence Theorems
- The ZFC Axioms and the Basic Set Constructions
- Topological Spaces and Continuity
- Topology of ℝ
2 · Logical flowchart
3 · Definitions, theorems and proofs
None yet.
4 · Examples, counterexamples and false statements
An inaccurate model can give the exact return on behavior support
Example
Let , with one dummy action at and actions at . At , action has reward and returns to . At , action has reward and moves to , while action returns to with true reward and learned reward . The true and learned models agree on and . Let the supported set be , let the initial state be , and let . A policy that chooses at and at has identical true and learned -step returns, although the learned model is wrong on the unsupported pair .
The TikZ diagram shows the two model transition/reward tables: a label gives action and its immediate reward on the arrow, and an arrow returning to its source denotes a self-transition. The learned reward for is marked with a hat.
\begin{center} \begin{tikzpicture}[>=stealth, node distance=32mm] \node[circle,draw] (s) {}; \node[circle,draw,right of=s] (g) {}; \draw[->] (s) to[bend left=12] node[above] {} (g); \draw[->] (g) to[loop right] node[right] {} (g); \draw[->] (s) to[loop left] node[left] {} (s); \end{tikzpicture} \end{center}
Example references
Facts & Assumptions
Given: The two-state models, supported set, initial law, horizon, and policy in the Example.
Finite learned transition and reward models: the true and learned reward means lie in , and each transition row is a probability distribution.
Finite-horizon simulation bound for one fixed policy: for a common initial law and fixed Markov policy, uniform errors on the union of reachable pairs give the stated finite-horizon return bound.
Verification
Given: The finite models and policy in the Example.
The true and learned occupancies under the policy place mass only on at time and on at each later time. These pairs are exactly the listed supported pairs, and the models agree on both, so the reachable reward and transition errors are zero. Theorem [F2] applies with .
Substitution into [F2] gives . Since an absolute value is nonnegative, . Directly, each return is from the reward at the first step and thereafter. Thus model errors outside the fixed policy's support do not affect this return.
A small transition error accumulates over longer rollouts
Example
Let the states be (safe) and (failure), each with one action. Both true and learned rewards are at and at . The true model stays at with probability , while the learned model moves from to with probability and stays at with probability , where ; both models keep absorbing. Starting at and following the only policy for horizon , the true return is and the learned return is .
The diagram compares the true transition model on the left with the learned transition model on the right. Nodes are states, and arrows carry transition probabilities; each state label gives its reward. The dashed arrow is present only in the learned model.
\begin{center} \begin{tikzpicture}[>=stealth, node distance=25mm] \node[circle,draw] (u1) {}; \node[circle,draw,right of=u1] (v1) {}; \draw[->] (u1) to[loop above] node[above] {} (u1); \draw[->] (v1) to[loop right] node[right] {} (v1); \node at (1.25,-0.8) {true}; \begin{scope}[xshift=7cm] \node[circle,draw] (u2) at (0,0) {}; \node[circle,draw] (v2) at (2.8,0) {}; \draw[->] (u2) to[loop above] node[above] {} (u2); \draw[->,dashed] (u2) to[bend left=12] node[above] {} (v2); \draw[->] (v2) to[loop right] node[right] {} (v2); \node at (1.4,-0.8) {learned}; \end{scope} \end{tikzpicture} \end{center}
Example references
Facts & Assumptions
Given: The two-state models, initial state, policy, error parameter, and horizon in the Example.
Finite learned transition and reward models: each model has probability transition rows and rewards in ; transition error is total variation.
Finite-horizon simulation bound for one fixed policy: a fixed policy with zero reward error and transition error at most on its reachable pairs has return discrepancy at most from a common initial state.
Verification
Given: The finite model pair and policy in the Example.
Under the true model, the state remains , so each of the rewards is and . Under the learned model, the probability of occupying at time is , by induction from the transition row, and the only positive reward is received at . Hence .
The reward error is zero. At , the total variation between the true row and learned row is ; at the rows agree. Every reachable pair therefore satisfies the hypotheses of [F2], and . The exact difference from step 1.1 is , which is nondecreasing in and is positive for . Thus even a fixed, small one-step transition error can produce a larger return discrepancy on longer rollouts, within the finite-horizon bound.
A one-step optimizer selects a falsely rewarding unsupported action
Example
There is one state , two actions and , and both actions return deterministically to . Their true rewards are and , respectively; their learned rewards are and . Let , let , and let the finite policy class contain the two policies that choose one action at time . Supply MPC with the ordered action listing at . Finite-horizon model-predictive control chooses , whose predicted return is and true return is , while the true best return in the class is .
The diagram uses a vertex for the state and a loop for each deterministic self-transition; each loop label gives the action and its true/learned immediate rewards.
\begin{center} \begin{tikzpicture}[>=stealth] \node[circle,draw] (s) at (0,0) {}; \draw[->] (s) to[loop above] node[above] {} (s); \draw[->] (s) to[loop below] node[below] {} (s); \end{tikzpicture} \end{center}
Example references
Facts & Assumptions
Given: The one-state model pair, data set, horizon, and policy class in the Example.
Model exploitation under support shift: a policy is model-optimal if it attains the learned return maximum in the finite policy class; off-support exploitation additionally requires positive learned occupancy on an unsupported pair, overprediction, and true suboptimality.
Finite-horizon model-predictive control: at horizon one, the returned action maximizes the learned immediate reward, with the complete supplied action listing used only to break ties.
Verification
Given: The finite model pair and class in the Example.
The two horizon-one learned returns are and , so is the unique learned optimizer and [F2] returns it. Its learned occupancy on is , although this pair is outside .
The true returns of and are and . Thus the learned optimizer overpredicts its own return () and is truly suboptimal (). All three clauses of [F1] hold, so this is off-support model exploitation as defined.