def add_glider(pos, mat):
    """ Add glider to state at given position (row, col)
    """
    row, col = pos

    mat[row, col-1] = 1
    mat[row+1, col] = 1
    mat[row+1, col+1] = 1
    mat[row, col+1] = 1
    mat[row-1, col+1] = 1

    return mat