[PPL-devel] Equivalent dimensions

[P M Hill]

On Thu, 21 Jul 2005, Mario Mendez wrote:

> Thank you! Another question then:
>
> How can I insert dimensions in the middle?
> E.G: convert
> 	[B=2,E=8]  Dim= N
> in      [B=2,G=8]  Dim = N + 2
> after inserting two "universe" dimensions between the original B and E. I 
> already know how to add at the beginning/end, but no idea about how to use 
> the library for this particular purpose.

I am not completely clear. If you mean that you want to insert two 
dimensions between the "B" and "C" dimensions, and rename the "E" 
dimension as "G", then here is a snippet of Prolog that does this.

   T = c,
   ppl_new_Polyhedron_from_space_dimension(T, 5, universe, P),
   ppl_Polyhedron_add_constraints(P, [B = 2, E = 8]),
   ppl_Polyhedron_add_space_dimensions_and_embed(P, 2),
   ppl_Polyhedron_map_space_dimensions(P,
         [A-A, B-B, C-E, D-F, E-G, F-C, G-D]),
   ppl_new_Polyhedron_from_space_dimension(T, 7, universe, Q),
   ppl_Polyhedron_add_constraints(Q, [B = 2, G = 8]),
   ppl_Polyhedron_equals_Polyhedron(P, Q).


Basically, I have added the 2 new dimensions to the end and then use the 
"map_space_dimensions" predicate to rearrange the order of the dimensions.

>
> PS: I'm working in a abstract domain based on your library for finding linear 
> invariants....
>

Best wishes,
   Pat