Aryeh Leib Taurog asked:
It seems to me that the lenth of each cycle includes the both sightings. That is if she sees on day 1 and again on day 22, we call that a 22-day cycle. If so, Rav Papa's example on the top of 39b is that she sees on days 1, 22, and 43 (not 44 as you have it). After she saw on day 27 instead, then according to R' Papa, she should be chosheshes for days 43 and 48, not 44 and 49. Day 43 would be, as Rashi points out, day 17 to her most recent sighting on day 27.
Do you agree?
Aryeh Leib Taurog, Jerusalem, Israel
The Kollel replies:
You are correct. See Rema YD 189:13 where it is clear that day twenty is counted twice, hence the next sighting is expected on ninth of Iyar (not tenth).
Dov Freedman