Tricki

## Prove the result on a delta-net first

### Quick description

In probabilistic arguments, one sometimes wants to prove that it is possible for a statement to be true for every element of an infinite set, and one knows that for each element of the set a slightly stronger statement is true with probability at least for some very small . If there is a natural metric on the set, one can sometimes achieve this by proving that the set contains a -net of size , and also that if the stronger result holds for every element of a -net, then the weaker result holds everywhere. Techniques for proving the existence of small -nets can be found in the article Finding small nets.