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    • CommentRowNumber1.
    • CommentAuthorMarkSaving
    • CommentTimeJun 29th 2022

    Change 1: Original page describes the fan theorem as requiring the bar to be decidable, claims that the “classical” fan theorem contradicts Brouwer’s continuity principle. The latter claim is not true; I corrected the error. I have stated the result as two separate theorems: the decidable fan theorem, about decidable bars, and the fan theorem, about bars in general.

    Change 2: Slightly more information is provided about the relationship between the Fan Theorem and Bar Induction. Eventually, we should make a page about the latter.

    Change 3: the section on equivalents to the fan theorem has been fixed somewhat. The section originally asserted that all of the statements provided were equivalent to the decidable fan theorem; in fact, some are equivalent to the decidable fan theorem and some to the full fan theorem.

    diff, v22, current

    • CommentRowNumber2.
    • CommentAuthorMarkSaving
    • CommentTimeJun 29th 2022

    Change 1: Original page describes the fan theorem as requiring the bar to be decidable, claims that the “classical” fan theorem contradicts Brouwer’s continuity principle. The latter claim is not true; I corrected the error. I have stated the result as two separate theorems: the decidable fan theorem, about decidable bars, and the fan theorem, about bars in general.

    Change 2: Slightly more information is provided about the relationship between the Fan Theorem and Bar Induction. Eventually, we should make a page about the latter.

    Change 3: the section on equivalents to the fan theorem has been fixed somewhat. The section originally asserted that all of the statements provided were equivalent to the decidable fan theorem; in fact, some are equivalent to the decidable fan theorem and some to the full fan theorem.

    diff, v22, current

    • CommentRowNumber3.
    • CommentAuthorMarkSaving
    • CommentTimeJun 29th 2022

    Change 1: Original page describes the fan theorem as requiring the bar to be decidable, claims that the “classical” fan theorem contradicts Brouwer’s continuity principle. The latter claim is not true; I corrected the error. I have stated the result as two separate theorems: the decidable fan theorem, about decidable bars, and the fan theorem, about bars in general.

    Change 2: Slightly more information is provided about the relationship between the Fan Theorem and Bar Induction. Eventually, we should make a page about the latter.

    Change 3: the section on equivalents to the fan theorem has been fixed somewhat. The section originally asserted that all of the statements provided were equivalent to the decidable fan theorem; in fact, some are equivalent to the decidable fan theorem and some to the full fan theorem.

    diff, v22, current

    • CommentRowNumber4.
    • CommentAuthorMarkSaving
    • CommentTimeJun 29th 2022

    Change 1: Original page describes the fan theorem as requiring the bar to be decidable, claims that the “classical” fan theorem contradicts Brouwer’s continuity principle. The latter claim is not true; I corrected the error. I have stated the result as two separate theorems: the decidable fan theorem, about decidable bars, and the fan theorem, about bars in general.

    Change 2: Slightly more information is provided about the relationship between the Fan Theorem and Bar Induction. Eventually, we should make a page about the latter.

    Change 3: the section on equivalents to the fan theorem has been fixed somewhat. The section originally asserted that all of the statements provided were equivalent to the decidable fan theorem; in fact, some are equivalent to the decidable fan theorem and some to the full fan theorem.

    diff, v22, current

  1. Expanded the referred content of the cited paper

    Anonymous

    diff, v23, current

  2. updated link to Martin Hyland pdf

    Anonymouse

    diff, v26, current

  3. added redirect for full fan theorem

    Anonymouse

    diff, v28, current

  4. Added reference

    Anonymouse

    diff, v30, current

  5. Added reference

    Anonymouse

    diff, v30, current

  6. added definition of a stable bar and the stable fan theorem.

    Anonymouse

    diff, v31, current

  7. Added fact that the WLPO for the natural numbers implies the stable fan theorem.

    Anonymouse

    diff, v31, current