# import necessary packages # import numpy as np The following code imports a matrix from the file mat.npy and stores it as mati. It also imports a vector from vect.npy and stores it as vect1. For objects like arrays, this can be much simpler than the more general methods in the sample files mat1 = np. load ("mat .npy.) vect1 = np.load('vect.npy') print('This is a positive definite matrix A ', mat1, " and this is a vector b ', vect1) ... Replace this comment with code write a function to perform forward substitution to solve the matrix equation 6x = b assume G is invertible and lower triangular the function should return the solution vector x the function should work for square matrices of any size ... return(x)