Hi all, I’ve spent the last few days working on Exercise 12, at the end of Chapter 5 of Ralf Hinze’s paper, “Fun with Phantom Types”. (Thanks, Conal, for all the help!) I thought I’d share my code, in case anyone else happens to be in the same Haskell space-time as me, right now. :) https://github.com/capn-freako/Haskell_Misc/blob/master/norm_by_eval.hs I hope everyone is enjoying their weekend. Cheers, -db