This will be a talk on the proof of NP hardness of the Art Gallery Problem (which was described by Pritam last week). Approximation algorithms for the terrain guarding problem will also be described.

Logic (first order or temporal) can be easily extended to describe counts, parity and other numerical phenomena. The satisfiability problem of the extended logic is easily seen to be undecidable, even on models which are finite words.

This talk will be an introduction to Social Choice Theory, which analyses methods to combine preferences of large number of voters to obtain a result that is fair .