# Lecture 04: Substitutions

Recorded at MIT on February 12, 2003. Running time for this class is 50 minutes.

- Kind: Talk
- Year: 2003
- By: AMPS, Massachusetts Institute of Technology
- Genres: Education, Science
- Archive: [Internet Archive](https://archive.org/details/mit-ocw-18.03-lec04)
- Licence or status: [CC BY-NC-SA 2.0](http://creativecommons.org/licenses/by-nc-sa/2.0/) (as the archive states it)
- Who can watch: Tweens profiles and older (the archive gives no rating; placed by Invisible Network from its collection and subjects)

[Watch now](https://invisiblenetwork.ai/watch/archive/ia/mit-ocw-18.03-lec04?play=1)