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, 42 insertions, 0 deletions

diff --git a/src/theory/arith/constraint_forward.h b/src/theory/arith/constraint_forward.h
new file mode 100644
index 000000000..dd0c1f2f6
--- /dev/null
+++ b/src/theory/arith/constraint_forward.h
@@ -0,0 +1,42 @@
+/*********************                                                        */
+/*! \file constraint_forward.h
+ ** \verbatim
+ ** Original author: taking
+ ** Major contributors: none
+ ** Minor contributors (to current version): none
+ ** This file is part of the CVC4 prototype.
+ ** Copyright (c) 2009, 2010, 2011  The Analysis of Computer Systems Group (ACSys)
+ ** Courant Institute of Mathematical Sciences
+ ** New York University
+ ** See the file COPYING in the top-level source directory for licensing
+ ** information.\endverbatim
+ **
+ ** \brief Forward declarations of the ConstraintValue and ConstraintDatabase classes.
+ **
+ ** This is the forward declarations of the ConstraintValue and ConstraintDatabase
+ ** and the typedef for Constraint.  This is used to break circular dependencies and
+ ** minimize interaction between header files.
+ **/
+
+#include "cvc4_private.h"
+
+#ifndef __CVC4__THEORY__ARITH__CONSTRAINT_FORWARD_H
+#define __CVC4__THEORY__ARITH__CONSTRAINT_FORWARD_H
+
+namespace CVC4 {
+namespace theory {
+namespace arith {
+
+class ConstraintValue;
+typedef ConstraintValue* Constraint;
+typedef const ConstraintValue* const ConstConstraint;
+
+static const Constraint NullConstraint = NULL;
+
+class ConstraintDatabase;
+
+}/* CVC4::theory::arith namespace */
+}/* CVC4::theory namespace */
+}/* CVC4 namespace */
+
+#endif /* __CVC4__THEORY__ARITH__CONSTRAINT_FORWARD_H */