Consider the discrete-time systems $ T_1 $ and $ T_2 $ defined as follows: $ [T_1x][n] = x[0] + x[1] + \dots + x[n], $ $ [T_2x][n] = x[0] + \frac{1}{2}x[1] + \dots + \frac{1}{2^n}x[n]. $ Which of the following statements is true?