[kaba0]

The linked text is pretty bad, having many mistakes. Please see the two comments at the end of the page.

For a better overview on what the projections are, please see http://blog.sigfpe.com/2009/05/three-projections-of-doctor-f... , or the original paper by Futamura.

[tekacs]

Thank you, this is super helpful -- I didn't look close enough to spot that myself. :)