It would be fun to subclass null, and make multiple instances of it. I did hack MACLISP to have multiple NILs once. A surprising number of things appeared to

It would be fun to subclass null, and make multiple instances of it. I did hack MACLISP to have multiple NILs once. A surprising number of things appeared to run OK for a while. Of course the PDP-10 had a hardware addressing mode just for NIL so if you weren't the official one compiled code didn't believe you were a legit NIL. Making another T was more boring, except that the few bugs that were triggered seemed to appear more quickly than in the NIL case. I guess a lot more people explicitly compared with 'T. Eh, grad students, what do you expect? As to why I did this, well it was decades ago but surely a case of work avoidance.