The fourth slur, added by GE and EE, almost certainly resulted from an arbitrary revision, frequently encountered in Chopin's pieces; it consists in 'completing' slurs between the given chords – for example, if, like here, 3 slurs linked two four-note chords, it would be considered a mistake, and the 'missing' slur would be added (cf., e.g. the Mazurka in D, Op. 33 No. 3, b. 8-9 and analog. or in B, Op. 41 No. 2, b. 4-5 and analog.).
Compare the passage in the sources »
category imprint: Differences between sources
issues: EE revisions, GE revisions
notation: Slurs