Showering just now, thinking about transparency, invisibility, opacity, inscrutability, other optical effects & tricks of light.
Babbage never designed a dialectical engine, should've, would've saved me a lot of bother. Shoulda, woulda, coulda.
Anyway, happy xmas, Ada, wherever you went- I'll try & do some amusing complex sums in my head for you while I work, know how that amuses you.
Knowhow, no way, no how.