factor q^k.
The contrapositive to the result:
If sigma(q)/n < sigma(n)/q, then sigma(q) < sigma(n).
is:
If sigma(n) < sigma(q), then sigma(n)/q < sigma(q)/n.
But:
If sigma(n)/q < sigma(q)/n, then n < q.
Therefore:
If sigma(n) < sigma(q), then n < q.
{q, sigma(q), n, sigma(n)} is:
Case #1: n < sigma(n) <= q < sigma(q).
The contrapositive of:
If sigma(n) < sigma(q), then n < q.
is:
If q < n, then sigma(q) < sigma(n).
{q, sigma(q), n, sigma(n)} is:
Case #2: q < sigma(q) < n < sigma(n).
The resulting inequality in a third case that comes to mind
for the quantities {q, sigma(q), n, sigma(n)} is:
Case #3: n < q < sigma(q) < sigma(n).