Apollo 11 - In Theaters
url: http://trailers.apple.com/trailers/independent/apollo-11/
The Hours And Times - Trailer
url: http://trailers.apple.com/trailers/oscilloscope/the-hours-and-times/
The Iron Orchard - Clip
url: http://trailers.apple.com/trailers/independent/the-iron-orchard/
Ash Is Purest White - Trailer
url: http://trailers.apple.com/trailers/independent/ash-is-purest-white/
Differentiation and Integration
"Symbolic integration" is when you theatrically go through the motions of finding integrals, but the actual result you get doesn't matter because it's purely symbolic.