How do i code into maple to check if a matrix is diagonally dominant?

s:=Matrix([[2,1,2],[-5/4,-5,5/4],[21/5,-14/5,7]]):
 

s[1,1];

2

s[1,2] + s[1,3];

3


this is what av done so far but i dont think its correct

for i from 1 to 3 do
for j from 1 to 3 do

s[i,i] <= s[i,j] + s[i,j+1]

od:od:

I have a problem i am trying to see how long it takes for my program to give a solution but the time keeps on changeing everytime i press enter. I can't seem to understand why?
 

I was wondering is it possible to make a procedure in maple that works out the Bisection, tri section using a single procedure?

So for example for the bisection method c : =( a + b ) /2
fAnd  trisection method c : = ( 2 * a + b) / 3 and d : = (2 * b + a )/3 etc

For n th section L [ i ] :=( i*b + a ( n - i ) ) / n:
` i ` represents the position in a List.

e.g (Not sure if it would work in a proc)
Trisection
n:=3:
i:=1:
L:= [ c , d ]:

L[ 1 ]:= ( b + 2 * a ) / 3:

Initial conditions,     x(0)=2, D(x(0))= -2

D= differential

D2x +5Dx +4x = delta( t - 2 )
 

I want to check my answer in maple but i cant get it to work.

This is the answer i gt by hand

x = H( t - 2 ) ( ( e ^ - 4 ( t - 2 ) + e ^ - ( t - 2) ) / 3 ) - 4 / 3 e ^ - 4 ( t - 2 ) + 10 / 3 e ^ - ( t - 2 )

I need help on turning this code into a procedure and what changes do i have to make  so it works like the gauss-seidel algorithm. I have tried many times on my own but can't seem to get my head around it. Any help would be appriciated greatly.