According to us, placing 
in A only at the beginning of bar 1 is an example of Chopin's using a manner of putting the indications inside, and not at the beginning of, the area of their validity, which is not used at all today. It is also possible that Chopin feared the suggestion that the indication refers only to the L.H., yet this risk also seems to be negligible in our times. In FC Fontana put the sign slightly earlier, so that in GE1 it was printed at the very beginning of the piece. The interpretation was reviewed in GE2 (→GE3).
Compare the passage in the sources »
category imprint: Differences between sources
issues: GE revisions, Inaccuracies in FC, Centrally placed marks
notation: Verbal indications