Colloquium of Mathematical Logic, June 17, 5:00 p.m. (UTC +3), via Google Meet Dedicated to the 85th Anniversary of Prof. Dimiter Skordev Prof. Dimiter Skordev (Sofia University "St. Kliment Ohridski") will deliver a lecture on A variant of the system PA: with exponentiation instead of addition and multiplication Online Colloquium via Google Meet Join Google Meet Meeting