Using Your Opponent's Strength Part 3

I talked to my teacher today about what to do if I cannot lu my opponent's arm because he sinks his elbow. After all, if I try to roll back on his arm, I will end up using brute force to turn his arm around and pull it downwards. Since that is against taiji's principle of not applying brute force, what should I do?

My teacher's answer was very simple. You don't need to go up against his force. If he sinks his elbow downwards, his force is downwards. So trying to lift up his arm, turn it around and then pull it downwards is to actually go up against his downwards force. This is ding. What I can do here is not to try to lu anymore, but to just turn my palm around and push his elbow towards his body instead. Since his force is downwards, my force towards his body is unopposed and I will then be able to push him down.

I will try to upload some photos of what I am trying to say. Have to find a few people to "model" first.