## Department of Mathematics

Indian Institute Of Technology Madras , Chennai
• Office of the Department of Mathematics is moved from HSB to New Academic Complex (NAC) 5th and 6th Floor

### A curious ball game

#### Abstract :

We present a ball game demonstrating a possible gap between truth and provability in arithmetic. The puzzle is solved using König's Lemma on Infinite trees. Further formalisatiom leads to Tarski's inexpressibility of truth, Gödel's first incompleteness theorem and $\omega$-incompleteness of arithmetic. Only high school level mathematics and familiarity with logical quantifiers like forall, exists and connectives such as negation, implication are assumed.

Key Speaker Arindama Singh
Place NAC 522
Start Time 3:00 PM
Finish Time 4:00 PM