With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Amazon Web Services included mobile tools.
text_B: In the field of mathematics known as convex analysis , the characteristic function of a set is a convex function that indicates the membership -LRB- or non-membership -RRB- of a given element in that set .. mathematics. mathematics. convex analysis. convex analysis. convex function. convex function. It is similar to the usual indicator function , and one can freely convert between the two , but the characteristic function as defined below is better-suited to the methods of convex analysis .. convex analysis. convex analysis. indicator function. indicator function
not_related.