In mathematics, a B-convex space is a type of Banach space. The concept of B-convexity was related to the strong law of large numbers in Banach spaces by Anatole Beck in 1962; accordingly, it is sometimes referred to as Beck convexity. Beck showed that a Banach space is B-convex if and only if every sequence of independent, symmetric, uniformly bounded and Radon random variables in that space satisfies the strong law of large numbers. Let X be a Banach space with norm . X is said to be B-convex if for some 0 and some natural number n, it holds true that whenever x1, ..., xn are elements of the closed unit ball of X.