Multiprecision matrix package test program.

Enter size of a square matrix A: Enter entries of A: A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
Creating an array of 3 matrices
 A=
[[1,2,3],
[4,5,6],
[7,8,9]]
2A=
[[2,4,6],
[8,10,12],
[14,16,18]]
3A=
[[3,6,9],
[12,15,18],
[21,24,27]]
row(A,1) = [1,2,3]
row(A,2) = [4,5,6]
row(A,3) = [7,8,9]
A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
col(A,1) = [1,4,7]
col(A,2) = [2,5,8]
col(A,3) = [3,6,9]
A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
directsum(A,A) = 
[[1,2,3,0,0,0],
[4,5,6,0,0,0],
[7,8,9,0,0,0],
[0,0,0,1,2,3],
[0,0,0,4,5,6],
[0,0,0,7,8,9]]
Enter any number After shortening to a matrix of ints, A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
B = A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
Enter any number B==A?1
B!=A?0
after B+:=A, A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
and B = 
[[2,4,6],
[8,10,12],
[14,16,18]]
Enter any number after B-:=A, A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
and B = 
[[1,2,3],
[4,5,6],
[7,8,9]]
Enter any number after B*:=2, A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
and B = 
[[2,4,6],
[8,10,12],
[14,16,18]]
Enter any number after B/:=2, A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
and B = 
[[1,2,3],
[4,5,6],
[7,8,9]]
Enter any number A+B=
[[2,4,6],
[8,10,12],
[14,16,18]]
Now A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
and B = 
[[1,2,3],
[4,5,6],
[7,8,9]]
Enter any number A-B=
[[0,0,0],
[0,0,0],
[0,0,0]]
Now A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
and B = 
[[1,2,3],
[4,5,6],
[7,8,9]]
Enter any number A*B=
[[30,36,42],
[66,81,96],
[102,126,150]]
Now A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
and B = 
[[1,2,3],
[4,5,6],
[7,8,9]]
Enter any number -A=
[[-1,-2,-3],
[-4,-5,-6],
[-7,-8,-9]]
Now A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
-A=
[[-1,-2,-3],
[-4,-5,-6],
[-7,-8,-9]]
Now A = 
[[1,2,3],
[4,5,6],
[7,8,9]]
Enter any number char. poly. of A has coefficients [ 0 -18 -15 1 ]
det(A) = 0
Augmented matrix = 
[[1,2,3,1,0,0],
[4,5,6,0,1,0],
[7,8,9,0,0,1]]

Which echelon method? (0=standard,1=longlong,2=modular) Echelon matrix = 
[[3,0,-3,0,-8,5],
[0,3,6,0,7,-4],
[0,0,0,3,-6,3]]
pivotal columns: [1,2,4]
nonpivotal columns: [3,5,6]
Denom = 3
Rank = 2
Nullity = 1
A is not invertible; rk = 2