Merges branches/arithmetic/atom-database r2979 through 3247 into trunk. Below is a highlight of the changes:

- This introduces a new normal form to arithmetic.
-- Equalities and disequalities are in solved form.
   Roughly speaking this means: (= x (+ y z)) is in normal form.
   (See the comments in normal_form.h for what this formally requires.)
-- The normal form for inequality atoms always uses GEQ and GT instead of GEQ and LEQ.
   Integer atoms always use GEQ.
- Constraint was added to TheoryArith.
-- A constraint is a triple of (k x v) where:
--- k is the type of the constraint (either LowerBound, UpperBound, Equality or Disequality),
--- x is an ArithVar, and
--- v is a DeltaRational value.
-- Constraints are always attached to a ConstraintDatabase.
-- A Constraint has its negation in the ConstraintDatabase [at least for now].
-- Every constraint belongs to a set of constraints for each ArithVar sorted by the delta rational values.
-- This set can be iterated over and provides efficient access to other constraints for this variable.
-- A literal may be attached to a constraint.
-- Constraints with attached literals may be marked as being asserted to the theory (sat context dependent).
-- Constraints can be propagated.
-- Every constraint has a proof (sat context dependent).
-- Proofs can be explained for either conflicts or propagations (if the node was propagated). (These proofs may be different.)
-- Equalities and disequalities can be marked as being split (user context dependent)
- This removes and replaces:
-- src/theory/arith/arith_prop_manager.*
-- src/theory/arith/atom_database.*
-- src/theory/arith/ordered_set.h
- Added isZero(), isOne() and isNegativeOne() to Rational and Integer.
- Added operator+ to CDList::const_iterator.
- Added const_iterator to CDQueue.
- Changes to regression tests.

1 files changed, 15 insertions, 19 deletions

diff --git a/src/theory/arith/arith_rewriter.cpp b/src/theory/arith/arith_rewriter.cpp
index 30568c3ca..863eb5c31 100644
--- a/src/theory/arith/arith_rewriter.cpp
+++ b/src/theory/arith/arith_rewriter.cpp
@@ -204,34 +204,30 @@ RewriteResponse ArithRewriter::postRewriteMult(TNode t){
   return RewriteResponse(REWRITE_DONE, res.getNode());
 }
 
-RewriteResponse ArithRewriter::postRewriteAtomConstantRHS(TNode t){
-  TNode left  = t[0];
-  TNode right = t[1];
+// RewriteResponse ArithRewriter::postRewriteAtomConstantRHS(TNode t){
+//   TNode left  = t[0];
+//   TNode right = t[1];
 
-  Comparison cmp = Comparison::mkNormalComparison(t.getKind(), Polynomial::parsePolynomial(left), Constant(right));
+//   Polynomial pLeft = Polynomial::parsePolynomial(left);
+  
 
-  Assert(cmp.isNormalForm());
-  return RewriteResponse(REWRITE_DONE, cmp.getNode());
-}
+//   Comparison cmp = Comparison::mkComparison(t.getKind(), Polynomial::parsePolynomial(left), Constant(right));
+
+//   Assert(cmp.isNormalForm());
+//   return RewriteResponse(REWRITE_DONE, cmp.getNode());
+// }
 
 RewriteResponse ArithRewriter::postRewriteAtom(TNode atom){
   // left |><| right
   TNode left = atom[0];
   TNode right = atom[1];
 
-  if(right.getMetaKind() == kind::metakind::CONSTANT){
-    return postRewriteAtomConstantRHS(atom);
-  }else{
-    Polynomial pleft = Polynomial::parsePolynomial(left);
-    Polynomial pright = Polynomial::parsePolynomial(right);
-
-    Polynomial diff = pleft - pright;
-
-    Constant cZero = Constant::mkConstant(Rational(0));
-    Node reduction = NodeManager::currentNM()->mkNode(atom.getKind(), diff.getNode(), cZero.getNode());
+  Polynomial pleft = Polynomial::parsePolynomial(left);
+  Polynomial pright = Polynomial::parsePolynomial(right);
 
-    return postRewriteAtomConstantRHS(reduction);
-  }
+  Comparison cmp = Comparison::mkComparison(atom.getKind(), pleft, pright);
+  Assert(cmp.isNormalForm());
+  return RewriteResponse(REWRITE_DONE, cmp.getNode());
 }
 
 RewriteResponse ArithRewriter::preRewriteAtom(TNode atom){