Both the change of indication from 
to 
and omission of the accent are most probably mistakes of the engraver of GE, although it is easier to imagine an overlooked 'z' in at the time of reading the autograph, hence in FE. Therefore, it is possible that one or both inaccuracies were initially present in FE, in which, however, Chopin corrected them in the last phase of proofreading.
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category imprint: Differences between sources
issues: Errors in GE, fz – f
notation: Verbal indications