# proof that every filter is contained in an ultrafilter

## Primary tabs

Type of Math Object:
Proof
Major Section:
Reference
Groups audience:

## Mathematics Subject Classification

### err...

I have never heard of a "subset of X" which is "not contained in X"... this is a very, very careless mistake.

### Re: err...

Evidently you're new to the site. Ray (user rspuzio) is one of the PlanetMath's most active contributors; please try not to be so careless yourself and properly follow the site's protocol by filing your correction via the "correct" button at the bottom of the object.

### Re: err...

I can do this, but the proof I know is fairly different than this one.

### Re: err...

I am now reading the guidelines, sorry for that...

### Re: err...

It was a simple misprint, which is now fixed.