[PPL-devel] [GIT] ppl/ppl(master): Mentioned a correction affecting PIP_Problem solution trees.

[Enea Zaffanella]

Module: ppl/ppl
Branch: master
Commit: 73dd768d9265a42d3c113f18e62d90948031b13d
URL:    http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=73dd768d9265a42d3c113f18e62d90948031b13d

Author: Enea Zaffanella <zaffanella at cs.unipr.it>
Date:   Mon Feb 14 08:36:29 2011 +0100

Mentioned a correction affecting PIP_Problem solution trees.
Mentioned an improvement in the generation of PIP_Tree_Node tautological
cnstraints, node splitting constraints and artificial parameters.

---

 NEWS |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/NEWS b/NEWS
index ebdbdb3..92a1c73 100644
--- a/NEWS
+++ b/NEWS
@@ -16,6 +16,11 @@ NEWS for version 0.12  (release date to be decided)
 New and Changed Features
 ========================
 
+o  The resolution process for PIP_Problem now better exploits the
+   integrality of parameters to simplify the newly generated tautological
+   constraints, the splitting constraints of decision nodes, and the
+   expressions defining artificial parameters.
+
 o  The implementations of the MIP and PIP solvers are based on a new
    data structure leading to significant space and time savings when
    the tableau matrix is sparse; the benchmarks of the ppl_lpsol demo
@@ -33,6 +38,10 @@ o  The input routine for PPL numeric datatypes has been extended to
 Bugfixes
 ========
 
+o  Corrected a problem in the simplification of PIP_Problem solution trees
+   whereby, under specific conditions, the node merging process produced
+   decision nodes that did not satisfy their class invariant.
+
 o  Corrected a problem in the input method for checked integers whereby,
    under specific conditions, the input stream state bits were not updated.
    The bug was only affecting builds using checked integer coefficients.