3. So let's relabel ''l''<sub>1</sub><sup>2</sup> and ''l''<sub>2</sub><sup>2</sup>, ''o''<sub>1</sub> and ''o''<sub>2</sub>, to show they are natural numbers like the ''n''s | 3. So let's relabel ''l''<sub>1</sub><sup>2</sup> and ''l''<sub>2</sub><sup>2</sup>, ''o''<sub>1</sub> and ''o''<sub>2</sub>, to show they are natural numbers like the ''n''s |