in 
The release of the pedal indicated at the beginning of b. 81 was not marked in A. It could have been intended by Chopin, since wherever a gradual pedal release sounds good, Chopin would often forgo the 
mark (cf., e.g. the Waltz in C
Minor, Op. 64 No. 1, b. 15 or the Concerto in F Minor, Op. 21, 3rd mov., b. 117-120). On the other hand, the likelihood of an oversight of is quite high due to the layout of A – the next pedalling marking and b. 83, which precedes it, are in the next line, which promotes various inaccuracies. In practice, the pedal could be released both analogously to b. 77, hence before the 4th beat of the bar, and at the end of b. 83. The latter actually does not require any further additions, hence the two [] marks in b. 81 and 83 suggested in the main text indicate, respectively, the shortest and longest possible pedal, not naturally resulting from the Chopinesque notation.
No pedalling markings at all in these bars is most probably an oversight of FC (→GE). In turn, the mark added in FE (→EE) by analogy with b. 77 is almost certainly inauthentic, since Fontana rather did not consult the corrections he performed in FE1 with Chopin.
Compare the passage in the sources»
category imprint: Differences between sources
issues: FE revisions, No pedal release mark
notation: Pedalling