It allows one to draw CAD drawings, convert drawn letters into labels, etc in a more natural way.
https://en.wikipedia.org/wiki/Sketchpad
As far as I know, Alan also greatly admires the work done at MIT in the 1970s like http://www.paulmckevitt.com/cre333/papers/putthatthere.pdf
It allows one to draw CAD drawings, convert drawn letters into labels, etc in a more natural way.
https://en.wikipedia.org/wiki/Sketchpad