[isabelle-dev] NEWS: Poly/ML heaps follow hierarchy of sessions

[Makarius]

On Thu, 17 Mar 2016, Lawrence Paulson wrote:

> This is a great achievement! And disk space is still important, 
> especially on modern devices with SSDs.

The main work is by David Matthews, and it happened over the past few 
years.

Without SML/NJ and old Poly/ML versions hindering us, we can now roar 
ahead much faster.


 	Makarius