Метод Холецкого для решения СЛАУ

A = [
    [10, 1, 1],
    [2, 10, 1],
    [2, 2, 10]
]
 
d = [12, 13, 14]
 
def choletsky_m(matrix, vector):
    n = m = len(matrix)
    b = [[0] * m for i in range(n)]
    c = [[0] * m for i in range(n)]
    for i in range(n):
        b[i][0] = matrix[i][0]
        c[0][i] = matrix[0][i]/b[0][0]
        c[i][i] = c[0][0] 
    for i in range(1, n):
        b[i][1] = matrix[i][1] - b[i][0] * c[0][1]
    c[1][2] = 1/b[1][1] * (matrix[1][2] - b[1][0] * c[0][2])
    b[2][2] = matrix[2][2] - (b[2][0] * c[0][2] + b[2][1] * c[1][2])
    return b, c
 
def choletsky_y(matrix, vector):
    y = [0] * len(matrix)
    y[0] = vector[0]/matrix[0][0]
    y[1] = 1/matrix[1][1] * (vector[1] - matrix[1][0] * y[0])
    y[2] = 1/matrix[2][2] * (vector[2] - matrix[2][0] * y[0] - matrix[2][1] * y[1])
    return y
 
def choletsky_x(matrix, vector):
    x = [0] * len(matrix)
    x[2] = vector[2]
    x[1] = vector[1] - matrix[1][2] * x[2]
    x[0] = vector[0] - matrix[0][1] * x[1] - matrix[0][2] * x[2]
    return x
 
def nevyazka(matrix, vector1, vector2):
    n = [0] * len(matrix)
    summ1, summ2, summ3 = 0, 0, 0
    for i in range(len(matrix)):
        summ1 += matrix[0][i] * vector1[i]
        summ2 += matrix[1][i] * vector1[i]
        summ3 += matrix[2][i] * vector1[i]
    n[0] = vector2[0] - summ1
    n[1] = vector2[1] - summ2 
    n[2] = vector2[2] - summ3
    return n
 
b, c = choletsky_m(A, d)
y = choletsky_y(b, d)
x = choletsky_x(c, y)
n = nevyazka(A, x, d)
 
print(f'Вспомогательная матрица В: {b}')
print(f'Вспомогательная матрица С: {c}')
print(f'Вспомогательный вектор Y: {y}')
print(f'Решение системы: {x}')
print(f'Невязка: {n}')