PSSL 91 - First announcement Dear Colleagues, We are pleased to inform you that the 91st Peripatetic Seminar on Sheaves and Logic will be held on the weekend of 27th-28th November 2010 in Amsterdam, The Netherlands. The seminar will be founded by NWO (The Netherlands Organisation for Scientific Research) and The Algebra & Coalgebra group of the ILLC. A second announcement with some practical information will follow next week. We apologise for the late notice but there was some delay with the reply of our founding source. We are looking forward to seeing you in Amsterdam! Best regards, The organisers Raul Leal, Vincenzo Ciancia, Johanes Marti [For admin and other information see: http://www.mta.ca/~cat-dist/ ]