In A Chopin wrote a 
raising a
to a only just before the last chord in this bar. The mistake remained unnoticed in the majority of the editions – the necessary accidental to the 2nd crotchet was added only in FE. In the main text we include this addition and put the to the 4th crotchet (unnecessary in this situation) at the pitch of c1 as a cautionary accidental.
In addition, all sources feature a to a1 on the 6th R.H. quaver (unnecessarily repeated), which we omit in the main text.
Compare the passage in the sources»
category imprint: Interpretations within context; Differences between sources; Editorial revisions
issues: FE revisions, Errors repeated in GE, Errors repeated in EE, Errors repeated in IE
notation: Pitch