GAME PROBLEM NEW ZELAND...i=i+o PROBLEM

t [·] = (0, 0);
while i < SAMPLE do
aa = mul (a[0][i], a[0][i])
ab = mul (a[0][i + 1], a[0][i + 1])
ac = mul (a[0][i + 2], a[0][i + 2])
ad = mul (a[0][i + 3], a[0][i + 3])
ae = add (aa, ab)
af = add (ac, ad)
t[0] = add (ae, af)
i = i + 4
end while

i should be = to (0,0) OR TO i+0
then
ae = add a incognit or a preposition or a number

end while
that's what I would like to know, thank you doods

TOO EASY...TO READ
https://researchspace.auckland.ac.nz/bitstream/handle/2292/4341/ASP20051093.pdf;jsessionid=2B563080CA75793EEA328865D96245CD?sequence=1