“…Indeed, it is known that if x, y ^ 0, then the relation + 2/|| = ||x|| + ||y|| holds if and only if x = ay for some real a > 0. The strict convexity has been generalized to the space having Property C [3], by which we mean that if ||x + y + z||/3 = ||x|| = ||j/|| = ||z|| = 1, then x,y and z are collinear. A strictly convex space has Property C, but the converse is not generally true ( [3], Example 1).…”