Aha, ok. I am very sorry. I did not know this rule. Ok. This is how I understood it:
1. The place of some sort of change? I am not sure if they are meaning like a start point of something?
Now the sentences: The position where the thing is present changes to the point where the movement ends is considered the point if that change. The second sentence I just have no idea... I mean i get the words when I look at them seperatly, but when i try to make any sense of it, I can't. :emoji_frowning2: