Need to add more info about dual numbers

 My interests are in category theory, infinitesimals, and applications to "everyday", macroscopic physics, like heat transfer, open-channel fluid flow, and reasoning about similarity.

 It would be good to see an entire science textbook (say, on physical oceanography) using infinitesimals when it needed to justify a calculation.

 euler characteristic and measure ... Tom Leinster

Synthetic DG

Books on SDG ; working on trying to make a simple one with classical DG results... Or just geometry in general...

x x x

can an infintesimal neighborhood of the diagonal be so simple??