System Design and Data Structures

1. What kind of "NEXSIS" do we want - data structures etc.
   How do we correct what we know is inefficient in SIS? All the things we do not like about SIS
   Should we make a "clean" SIS?
2. How do we get layout information into NEXSIS
3. Use of hierarchy - do we embed all this in VIS. Direct use of multi-valued variables? (paper by Malik?)