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File: [local] / OpenXM_contrib / PHC / Ada / Root_Counts / Symmetry / linear_symmetric_reduction.ads (download)
Revision 1.1.1.1 (vendor branch), Sun Oct 29 17:45:31 2000 UTC (23 years, 10 months ago) by maekawa
Import the second public release of PHCpack. OKed by Jan Verschelde. |
with Symmetry_Group; use Symmetry_Group; with Lists_of_Integer_Vectors; use Lists_of_Integer_Vectors; package Linear_Symmetric_Reduction is -- DESCRIPTION : -- This package contains two routines that enable the faster -- solution of a symmetric product system, by extracting the -- generating positions. function Linear_Symmetric_Reduce ( sign : boolean ) return List; function Linear_Symmetric_Reduce ( v,w : List_of_Permutations ) return List; -- DESCRIPTION : -- Returns the generating list of positions in the random product system. -- REQUIRED : data in package Random_Product_System is not empty. procedure Linear_Symmetric_Reduce ( lp : in out List; sign : in boolean ); procedure Linear_Symmetric_Reduce ( v,w : in List_of_Permutations; lp : in out List ); -- DESCRIPTION : -- Given a (G,V,W)-symmetric product system, a list of positions -- that indicate the generating subsystems will be returned. -- REQUIRED : data in package Random_Product_System is not empty. -- ON ENTRY : -- v,w group representations, -- if not provided, then the full permutation group is assumed; -- sign if true, then there is also sign symmetry to consider; -- lp a list of positions, indicating the useful -- linear systems in the product system. -- ON RETURN : -- lp a sublist of the former list, -- contains only the generating linear systems. end Linear_Symmetric_Reduction;