2020 Summer Olympics
The 2020 Summer Olympics, officially known as the and commonly known as Tokyo 2020, is a forthcoming international multi-sport event that is scheduled to take place from 24 July to 9 August 2020.
Proof by exhaustion
Proof: the first modern Summer Olympics were held in 1896, and then every 4 years thereafter (neglecting years in which the games were not held due to World War I and World War II). Since 1896 = 474 × 4 is divisible by 4, the next Olympics would be in year 474 × 4 + 4 = (474 + 1) × 4, which is also divisible by four, and so on (this is a proof by mathematical induction). Therefore the statement is proved.