def mulrowcol(row, col, K):
    """
    Multiplies two lists representing row and column element-wise.

    Gotcha: Here the column is represented as a list contrary to the norm
    where it is represented as a list of one element lists. The reason is
    that the theoretically correct approach is too expensive. This problem
    is expected to be removed later as we have a good data structure to
    facilitate column operations.

    Examples
    ========

    >>> from sympy.matrices.densearith import mulrowcol
    >>> from sympy import ZZ

    >>> a = [ZZ(2), ZZ(4), ZZ(6)]
    >>> mulrowcol(a, a, ZZ)
    56

    """
    result = K.zero
    for i in range(len(row)):
        result += row[i]*col[i]
    return result