In A (→FC,FE) there is not a single accidental before the 13th and the 15th semiquavers. In the face of the 
before the 3rd semiquaver, placed graphically at the same pitch (a2), one can have doubts whether Chopin meant a3 or a
3. However, the arguments in favour of double a3 are definitely more numerous:
- formally speaking, the notation of A determines that very version, since in this context a
is not necessary; - oversights of cancelled alterations are one of the most frequently committed mistakes by Chopin;
- the absence of accidentals indicates that Chopin heard the same sound twice; in this melodic and harmonic context, a3 as the 15th note would be awkward;
- in analogous – despite the differences – b. 23 a3 is present twice.
EE features the version adopted by us (with a before the 13th note in the bar). In turn, the addition introduced into GE – a only just before the 15th note – does not dissipate all doubts concerning the sound of the 13th one, yet it suggests that they should differ, resulting in a3-b3-a3-g3, which, in turn, seems to be highly unlikely due to the close proximity of the altered and the natural notes.
Compare the passage in the sources »
category imprint:
notation: