Alphabeta Math
ExampleConstruction: AI-adaptedVerification: AI-generatedPipeline-generated
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.

A noncommunicating MDP can have state-dependent average reward

Example

Assume the Axiom of Choice for the path laws in the communicating-MDP definition. Let S={0,1} and let each state have one action. Both states are absorbing. The reward is always 0 in state 0 and always 1 in state 1. The MDP is not communicating, and its long-run average reward is 0 from initial state 0 and 1 from initial state 1.

Example references

Communicating-MDP hypothesis: Introduction, Definition 1; §2.

Communicating MDP and diameter: defines finite expected hitting between every ordered state pair.

Axiom of Choice: assumed for the policy path laws in that definition.

Facts & Assumptions

Given: The two-state MDP specified in the Example.

[F1]

Finite MDP with bounded real rewards: transitions and rewards are fixed conditional on the current state and action.

[F2]

Communicating MDP and diameter: communication requires finite optimal expected hitting time for every ordered pair.

[A1]

The Axiom of Choice: supplies the path-law convention used in [F2].

Proof

1.1givenF1construct

Starting from either state, the chain remains there at every time. From state 0 every cumulative reward is 0, so its average is 0; from state 1 every cumulative reward over T steps is T, so its average is 1.

2.1givenF1F2A1step 1.1algebra∎

No policy can leave either absorbing state. In particular, starting from 0 there is no policy that reaches 1 with finite expected hitting time, so [F2] says the communicating condition fails. The distinct averages show why the theorem's communication hypothesis matters.

Depends on

Used by

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