In the relative free trade Ricardian model, wouldn’t it be 1 ≤ p ≤ 3 not 1< p < 3?

Since country b are indifferent to selling good 1 or good 2, and country c is indifferent to selling either good at 3 as well, that means that p can exist on 1 and 3, correct? Because it can produce either good on both of those lines. Just one country would not be benefiting from the trade.