Le Chaud Lapin wrote:
I am trying to convince them that, if there is air on the inside of
the wing, it pushes against all sides of the inside of the wing,
including both top underside and bottom overside, and thereby
nullifying any effect it would have on the wing.

You are trying to convince one person - there is no plural.

Just for the record, I pointed the OP at the following NASA web pages and
after first thanking me, has decided NASA's explanation is somehow suspect:

http://www.grc.nasa.gov/WWW/K-12/airplane/lift1.html
http://www.grc.nasa.gov/WWW/K-12/airplane/right2.html
http://www.grc.nasa.gov/WWW/K-12/airplane/downwash.html

Note follow-ups set to sci.physics only.