Determining the beginning of the 
sign in A is not an easy task. It seems that at first Chopin started the hairpins between the 1st and 2nd quaver in bar 35, yet then he corrected them with a bolder line, moving the beginning to the 4th quaver in the bar. The lines remaining after the original entry were included in the slur embracing this phrase. The pair of 
signs defines in A the dynamic wave embracing bars 35-37, hence three-bar long.
The remaining two Stichvorlage manuscripts – FC and base text to EE – have longer signs, filling in fact the entire four-bar phrase. At the same time, the sign in EE is moved so clearly in comparison with the respective sign in FC that it seems to be highly unlikely that there is any source dependency between them. It leads to the conclusion that it was probably Chopin himself that wrote the discussed signs in all three Stichvorlage manuscripts. This means that he included with the dynamic wave the entire four-bar section twice and he omitted its last bar only once.
On the basis of the above analysis, in the main text we give the hairpins of FC, considering, however, the three-bar detail in A to be practically an equal, alternative version of dynamics.
We preserve the compatible with the manuscripts position of the signs over the part of the R.H. However, one cannot exclude that the reason for such placement could have simply been lack of space between the staves and moving them to the typical place, as it was performed in GE, is justified.
Lack of signs in FE, although puzzling, is, however, most probably a result of the engraver's inattention.
Compare the passage in the sources »
category imprint: Differences between sources
issues: Errors in FE, Scope of dynamic hairpins, GE revisions
notation: Articulation, Accents, Hairpins