The Gemara brings proofs for Rava and it brings the scattered coins proof as well as the proof of the Beis Medrash where the 'Rabbim' are found. The answers to both of these proofs is that a person will often check his pockets and therefore he has made 'Yeeoosh' and will know what he has lost. Are these proofs not very similar? What is the purpose of bringing two seemningly identical proofs? Does Rashi or Tosafot answer this question?
Akyva, Toronto, Canada
The second Tosfos on the page discusses this question.
D. Zupnik