In A (→FC,FE→EE1) and CGS there is no 
lowering b to b
. Chopin's mistake, obvious in this context, was corrected in GE and EE2. The fact that Chopin was convinced of the presence of b in the preceding part of the bar is evidenced by the naturals written in A before B1 and b on the 4th beat of the bar.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: EE revisions, GE revisions, Omission of current key accidentals, Errors of A, Errors repeated in FE, Errors repeated in EE
notation: Pitch