As
compare
b. 99
The slur over the pair of chords could have been added by Chopin in the proofreading of FE. In GE1Ab it was moved under the chords, as a result of which it can be considered to be a tie of f1.
Compare the passage in the sources »
category imprint: Differences between sources
issues: Placement of markings, GE revisions, Authentic corrections of FE
notation: Slurs