#範例2-7：三個矩陣相乘具有結合律
import numpy as np

A = np.array([
    [4, -1],
    [2, 3]
])
B = np.array([
    [5, 3],
    [0, 1]
])
C = np.array([
    [9, 8],
    [-6, 2]
])
print('(AB)C=\n', (A @ B) @ C)
print('A(BC)=\n', A @ (B @ C))