Yes, these are the Four Great Efforts. Two of them work on the side of letting go or preventing negative qualities or negative actions and speech, etc. The other two work on developing and maintaining positive, beneficial aspects of ourselves, our speech, our actions and such. So, first, the four get divided into two because they're working on different aspects. Now, it's interesting to see that they correlate very closely to the Compassion/Lovingkindness wish that we have here: on one side, wishing there are no difficulties; on the other side, wishing for more peace and happiness. So, the first two Great Efforts work on the Compassion side. The second two Great Efforts work on the Lovingkindness side.
Now, for examples of them, let's go back to the example we gave in an earlier answer of walking into the hall and seeing someone on your sitting mat. In order to prevent the aversion arising, you have to reflect upon Dukkha more often in your life. You have to reflect that this may happen to you, that you may actually come into the hall one day and see that someone's taken your mat. You have to reflect that you may come out of work one day and find that somebody's taken your car. You have to reflect that Dukkha can come at anytime, anywhere. The more you reflect in that way, and then if you happen to find out that your car is gone or your sitting mat is taken, no aversion comes up because you understand this is part of life; you knew it could happen. This happens to people all the time. It's part of life. This way, we prevent the aversion coming up. By having wisdom before a situation occurs, we prevent any negative reaction.
Now, if we miss preventing it, we have to rely on letting go. The Buddha's given us two chances here; if you miss the first one, you get a second go. If we can't prevent the aversion, we have to rely on letting go. If you come into the hall, someone's sitting on your mat, and the aversion arises, what are you going to do with it? Kick the person in the head? That's one way to deal with it, but it's not very skillful, of course. You can't speak in a retreat, so therefore, you can't really do much that you may normally do.
In normal life, you may say "Excuse me that's my mat," and the person may say, "Sorry," and get up and everything is fine. That's in normal life, but you can't do that here. So, if you have to work totally within yourself to let go of the aversion, can you have Compassion/Lovingkindness for this person who made a mistake? Can you realize that it doesn't really matter? For one sitting period, you can miss sitting on your mat. It doesn't really matter if they make it dirty; you can wash it at lunch time. What's the big deal? You know you can trade it with the assistants for a new one if it's too bad.
You can reflect in these various ways. You can look around the hall and think, "Well, I guess they left their mat somewhere else? Which one is up against the wall? I'll use that one." Or you can take it as a prime opportunity to learn how to sit without a mat. And then be free of having to use a mat. And then be free of having to worry about people taking your mat in the hall. I have no trouble with worries about people taking my mat. It's a nice freedom. It's something you might want to work towards. So, letting go depends on seeing the aversion, but then using all the wise reflection you can to help let go.
Now, the other two Efforts work in this situation, too. They're the efforts to Develop and Maintain. What are we going to develop? More Equanimity towards this type of situation. We're actually developing it while we work on the prevention or the letting go. We're actually developing more Wisdom that will guard us. So development, prevention and letting go get together here as far as this example goes. The more you develop the understanding of Dukkha, the more that will prevent you from having a negative reaction when Dukkha comes and the easier it will be to let go of any negative reaction that does arise. Nice. Now the efforts to Develop and Maintain are just looking at the same thing at a different time period. Developing is the beginning. Maintaining is from then on. So, first, you develop a bit of understanding of Dukkha; you reflect on it once. But maintaining it means you must reflect on it often. You must keep it fresh in the mind by reflecting on it often. So that's an example of how the Four Great Efforts - and they are great efforts that can help you in your life.