1. The followingbroadcategoriesofelemens are found in an SVRF rule file:

  layer assignments

  global layer definitions

  comments

  include statement

  rule check statements{ 

          local layer definitions

          layer operations

          rule check comments

         }

   specification statements

   connectivity extraction operations

   parasitic extration statements

   device recognition operations

   confitionals

   macros

   runtime TVF functions

2. Notice the presence of properties DV ,DG, and DA:

  DV (density value) : density value of the window (to eight significant figures).

  DG(density gradient): gradient value of the window if GRADIENT is specified.

  DA(density area) : area value of the window . It may either be followed by a numeric value , or by a layer name and then a numeric value .