  In 1930s Paul Erdos conjectured that for any positive integer C in any
infinite +1 -1 sequence (x_n) there exists a subsequence x_d, x_{2d}, ... ,
x_{kd} for some positive integers k and d, such that |x_d + x_{2d} + ... +
x_{kd}|> C. The conjecture has been referred to as one of the major open
problems in combinatorial number theory and discrepancy theory. For the
particular case of C=1 a human proof of the conjecture exists; for C=2 a
bespoke computer program had generated sequences of length 1124 having
discrepancy 2, but the status of the conjecture remained open even for such a
small bound. We show that by encoding the problem into Boolean satisfiability
and applying the state of the art SAT solvers, one can obtain a sequence of
length 1160 with discrepancy 2 and a proof of the Erdos discrepancy conjecture
for C=2, claiming that no sequence of length 1161 and discrepancy 2 exists. We
also present our partial results for the case of C=3.
