Let be a metric space, prove that is a metric over Moreover is bounded with the metric and
First part is easy, now I wanted to see how to prove that is bounded with the metric is it because ? Now since so since then then is this correct?
In general, you can prove this:
Let be a metric space, and be a increasing positive concave function with , roughly,
- on .
Then is a metric space, where defined by for .
The first condition is required for M1, and the last two is for M3,
you can see that M2 follows directly without any condition.
This was what I have proved when I was 2nd year BC.
You can also show what if .