It seems a double loop requires print()

I may have stumbled upon a loop quirk

for m from 1 to 5 do
  m;
end do;

                                                1
                                                2
                                                3
                                                4
                                                5

for n from 1 to 5 do
  for m from 1 to 5 do
     m;
  end do;
end do;

I get a return of nothing, I have to use print(m).  Is this a quirk with double loops?