b. 21
The fourth demisemiquaver of the 3rd group and the 3rd note of the 4th group should be interpreted in A (→FC→GE) as g2, since there are no accidentals next to them, and the note at this pitch in the 2nd group is provided with a . Both the harmonic context and the rule of the figurations' structure applied in a vast majority of the cases (cf. b. 4 and 13) are strong arguments in favour of the assumption that Chopin overlooked the restoring g2. The accidental was added in FE (→EE).
Compare the passage in the sources»
category imprint: Interpretations within context; Differences between sources
issues: Omissions to cancel alteration, Errors of A, FE revisions, Errors repeated in GE
notation: Pitch