def permutation_from_block_permutations(permutations):
    """Reverse operation to :py:func:`permutation_to_block_permutations`
    Compute the concatenation of permutations

        ``(1,2,0) [+] (0,2,1) --> (1,2,0,3,5,4)``

    :param permutations: A list of permutation tuples
                                 ``[t = (t_0,...,t_n1), u = (u_0,...,u_n2),..., z = (z_0,...,z_nm)]``
    :type permutations: list of tuples
    :return: permutation image tuple
                    ``s = t [+] u [+] ... [+] z``
    :rtype: tuple
    """
    offset = 0
    new_perm = []
    for p in permutations:
        new_perm[offset: offset +len(p)] = [p_i + offset for p_i in p]
        offset += len(p)
    return tuple(new_perm)
Reverse operation to :py:func:`permutation_to_block_permutations`
    Compute the concatenation of permutations

        ``(1,2,0) [+] (0,2,1) --> (1,2,0,3,5,4)``

    :param permutations: A list of permutation tuples
                                 ``[t = (t_0,...,t_n1), u = (u_0,...,u_n2),..., z = (z_0,...,z_nm)]``
    :type permutations: list of tuples
    :return: permutation image tuple
                    ``s = t [+] u [+] ... [+] z``
    :rtype: tuple