Lack of accidentals before the 5th pair of quavers in A means that Chopin either forgot to put a 
next to the upper note of the sixth (d3), or a 
one quaver earlier (d2). In a proofreading of FE (→EE) a flat was added, which is most probably a result of Chopin's intervention. Due to this fact, we give this version in the main text. In GE the flat was not included (probably it was not yet present in the proof copy of FE on which GE was based), yet a raising d2 to d3 was added. According to us, it is a revision, otherwise justified with the observation of Chopin's notation in this Etude, in which omissions of accidentals before the sixths' upper notes occur very frequently (e.g., in bars 5-8).
See b. 23
Compare the passage in the sources»
category imprint: Interpretations within context; Differences between sources
issues: EE revisions, Omissions to cancel alteration, GE revisions, Errors of A, Authentic corrections of FE
notation: Pitch