Write ups: K & E Log Log Vector Slide Rule Out of curiosity on how computation of complex domain elementary functions can be done, I got a rare 4083-3. For a 25cm straight slide rule the accuracy is about 3 to 4 digits with estimation, which is close to what today's half- precision binary floating-point can get. It lacks K scale for cubic square/root compared to the more common Decitrig model 4081, but the Log Log scales compensate for that. The supplement manual only did explain how to compute hyperbolic functions of complex numbers, but I am able to find other resources that gives the formula and it is a surprise the same formula is still used by Common Lisp and gives good accuracy. I have also added several uncommonly seen tricks not converged in the Decitrig manual to prove that Log Log Vector can compute anything that an electronic scientific calculator could do, albeit it needs skills and knowledge to close that gap.