We have a serious problem with how we have been teaching computability theory, a central component of the ACM/IEEE computer science curriculum.
Let me explain. For a fair number of years, I taught a computability course. Following the standard curriculum (such as described by Hopcroft and Ullman14), and in concert with my colleagues in the field, I made claims on countless occasions that one model of computation is more powerful than another or that two models have the same power of computation. In some cases the argument appealed to ordinary set inclusion, while at other times it involved a notion of simulation via encodings. Imagine my chagrin when I came to realize these two methods of comparison are in fact incompatible!
No entries found
Log in to Read the Full Article
Sign in using your ACM Web Account username and password to access premium content if you are an ACM member, Communications subscriber or Digital Library subscriber.
Please select one of the options below for access to premium content and features.
Create a Web Account
If you are already an ACM member, Communications subscriber, or Digital Library subscriber, please set up a web account to access premium content on this site.
Join the ACM
Become a member to take full advantage of ACM's outstanding computing information resources, networking opportunities, and other benefits.
Subscribe to Communications of the ACM Magazine
Get full access to 50+ years of CACM content and receive the print version of the magazine monthly.
Purchase the Article
Non-members can purchase this article or a copy of the magazine in which it appears.