WIP: still needs fixes in some files to build. (And then deprecation warnings, etc.)

Nooo, sorry, I'm almost done bumping myself 😅

Nooo, sorry, I'm almost done bumping myself 😅

No worries, just go ahead with your pr then, especially if you are further along

In fact, we barely duplicated effort as I spent a lot of time dealing with the deprecations and new simp normal forms, while you have fixed the proofs that gave actual errors. I will copy-paste the relevant changes to my WIP commit.

@YaelDillies The build should be fixed now, I won't work on the warning and simp hints when you are already doing this.
Seems like there are quite a few:

~/pfr (master)> lake build | grep warning | wc
    284    2409   26223

ok, should be good now: builds and all deprecation warnings are gone.

Oh, I realise we don't have CI setup for PRs from forks... Let me investigate quickly.