My point is that...
a formal proof is a very specific thing, and very few proofs that you'll find in the mathematical literature are formal proofs.
If you find this strange, then you either have no familiarity with what real math papers look like, or you don't really know what a formal proof looks like.
This applies as much at Dartmouth College, where I got my masters, as it does at Purdue and North Carolina. Furthermore if you talked to a logician from any of those three universities, I guarantee that they would agree with me.
All of this is well-known within the profession. It even has shown up on the wikipedia, for instance see [link|http://en.wikipedia.org/wiki/Mathematical_proof|http://en.wikipedia....athematical_proof].
Cheers,
Ben
