Hello, I'm Tam and I had a problem with Conditional of Jacobi Iteration.

So, the proplem is:

>restart;

>with(LinearAlgebra):

A:=Matrix([[5,1,-1],[0,4,2],[-1,2,-7]]);

And I want to check the condition

with the maple program.

Fisrt, I typed

b:=sum(abs('A'[1,j]),j=1..ColumnDimension(A)); and I got b:=7