def check_repeat_x(V):
    """
    Check if exists repeated x value

    Parameters
    ----------
        V : dict
            dictionary which contains X and Y values

    Returns
    -------
        bool
            Returns True if there are repeated x's values or 
            False if there are no repeated x's values
    """
    xlabel, _ = V.keys()
    return not(len(V[xlabel]) == len(set(V[xlabel])))