Retired electronics application engineer (originally telecomm mux stuff then microprocessor control apps), software design engineer (e.g., 80's, did communications software for email app in 1984 on multitasking platform, C and 8088 assembly), IT business owner (retired), former musician and recording engineer (search on "Dalton Bentley music"), original matriculation psychology, subsquent EE. Writer/editor (various venues, include computer user group journal editor 2003 - 2010). Martial artist (now more physical therapy than threat) Polymath (original university study in psychology and sociology, continued those fields, among others) and irritant, grin.

Recently got a kick out of programming in Python 3.7, my solution to the 1971 backtrack 0,1,2 sequences generator Dijkstra published as a problem for the reader (see pg 85 "Notes on Structured Programming" by Prof.dr. Edsger W. Dijkstra, 1970, Technological University Eindhoven, Netherlands, Department of Mathematics, Report 70-WSK-03).Dijkstra backtrack problem solution in Python

A while back I put together a tutorial for those new to the Isabelle Proof Assistant (a LaTex typeset document with plenty of screen shots, as well as cites), an interface between computers and mathematical reasoning I suppose: Isabelle Tutorial