Incidentally, I've also been thinking about dual quaternions for modeling rigid objects in 3d. For anyone who's curious about the topic, these seem to be a dece

Incidentally, I've also been thinking about dual quaternions for modeling rigid objects in 3d. For anyone who's curious about the topic, these seem to be a decent set of notes: http://web.cs.iastate.edu/~cs577/handouts/dual-quaternion.pdf http://web.cs.iastate.edu/~cs577/handouts/dual-quaternion.pd... Linear logic always reminded me of the no-cloning property in quantum physics, where a resource can only be used once -- no copying for multiple use. Can you elaborate on the sense in which you think of linear logic as "squaring to zero"? UPDATE: A little googling throws up this: http://www.seas.upenn.edu/~sweirich/types/archive/1999-2003/msg00520.html http://www.seas.upenn.edu/~sweirich/types/archive/1999-2003/...