issue #54: Removed duplicate piece of text in the end of chap_examples

doc/chap_examples.rst

@@ -858,7 +858,3 @@ Solving collision problem:
    robust longitudinal guidance. Proceedings of the 17th World Congress
    The International Federation of Automatic Control
    Seoul, Korea, July 6-11, 2008
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-Consider some moment of time :math:`t_1` and final position :math:`x_1(t_1) = x^1_1, x_2(t_1) = 0, x_3(t_1) = \frac{\pi}{2}, x_4(t_1) = 0`. It is required to calculate the backward reachability sets (tube) for the linearized system :eq:`invpendls` emanating from the given final position and project it onto :math:`(x_1, x_3)` subspace. It is also required to identify whether it’s possible to reach the final position from a given initial position :math:`x_1(t_0) = x^0_1, x_2(t_0) = v_1, x_3(t_0) = \theta_1, x_4(t_0) = \omega_1` using some admissible control function.
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