def sum_parameters(param):
    """
    Sums the equation parameters which have the same exponent and polynomial term.
    (a, ni, bi) and (c, ni, bi) become (a + c, ni, bi).
    
    Parameters
    -----------
    param: list
        list of tuples (Ai, ni, Bi)

    Returns
    ----------
    out: list
        list of tuples (Ci, ni, Bi).
    """
    # Dictionary of (ni, Bi): Ai
    Ai = {} 
    for x in param:
        try:
            Ai[x[1:]] += x[0]
        except KeyError:
            Ai[x[1:]] = x[0]
    return [(Ai[x], x[0], x[1]) for x in Ai]