[isabelle-dev] What is this 3 levels of lambda calculi?

[Makarius]

On Tue, 3 Mar 2015, Askar Safin wrote:

> Isabelle docs says that the system contains "3 levels of lambda calculi 
> with corresponding arrows =>, !! (aka \<And>) and ==>".

This is a plain isabelle-users question, not isabelle-dev. I will consider 
writing something about it on the other mailing list, but there might be 
other experts over there.


 	Makarius