With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Back to the Future Part II was written by Bob Gale not drawn.
text_B: In probability theory , the law of the iterated logarithm describes the magnitude of the fluctuations of a random walk .. probability theory. probability theory. random walk. random walk. The original statement of the law of the iterated logarithm is due to A. Y. Khinchin -LRB- 1924 -RRB- .. A. Y. Khinchin. Aleksandr Khinchin. Another statement was given by A.N. Kolmogorov in 1929 .. A.N. Kolmogorov. Andrey Kolmogorov
not_related.