Gittin 36: Public Vows, Courts Nullifying Vows of Other Courts

Vows taken in public are nullified by the public, as well.  The rabbis tell the story of a teacher who was "negligent" regarding his students - stories suggest he either hit the children too much or he ignored them.  Rav Acha vowed that he could no longer teach based on the consent of the public.  Ravina nullified Rav Acha's vow as they could not find a better teacher.  

Next, our daf teaches that witnesses sign documents with their full names to avoid problems related to identity at a later time.  Thus this is for the betterment of the world.  We learn in this conversation that different rabbis signed documents using pictorials: Rav dew a fish, Rabbi Chanina drew a palm branch, Rav Chisda drew the letter 'samech', Rav Hoshaya drew the letter ayin, and Rabba Rav bar Huna drew a sail.  These symbols, however, are unmistakable, and need not include the rabbis' full names.

The remainder of our daf focuses on the prosbol initiated by Rabbi Hillel the Elder.  Although lending and borrowing was excused for individuals over the Sabbatical year, shemita, courts could continue to demand payment of loans.  If loans were granted to those who were very poor/needy close to shemita, lenders were afraid that they would not receive back their payments.  Thus the prosbol allowed the courts to continue paying out/following up with the poor close to shemita.

The Gemara goes on to discuss whether Hillel instituted the prosbol only for his generation or for all generations.  To this end, the rabbis discuss what is done with ownerless property, when courts can nullify the decisions of other courts (when they are greater in number and in wisdom), and whether or not courts are collecting money when that is in fact prohibited.