Extra simplification rule.

git-svn-id: https://stp-fast-prover.svn.sourceforge.net/svnroot/stp-fast-prover/trunk/stp@1334 e59a4935-1847-0410-ae03-e826735625c1

diff --git a/src/AST/NodeFactory/SimplifyingNodeFactory.cpp b/src/AST/NodeFactory/SimplifyingNodeFactory.cpp
index dd3836e8bb457750683bcf02697192af07ba58b7..e7566f5d53af81ac6d452995ac1e58601ecae491 100644 (file)
--- a/src/AST/NodeFactory/SimplifyingNodeFactory.cpp
+++ b/src/AST/NodeFactory/SimplifyingNodeFactory.cpp
@@ -134,7 +134,8 @@ ASTNode SimplifyingNodeFactory::CreateNode(Kind kind, const ASTVec & children)
                       result = NodeFactory::CreateNode(BEEV::NOT, NodeFactory::CreateNode(BEEV::EQ, children[0], children[1]));
                 if (children[0].isConstant() && CONSTANTBV::BitVector_is_full(children[0].GetBVConst()))
                       result = NodeFactory::CreateNode(BEEV::NOT, NodeFactory::CreateNode(BEEV::EQ, children[0], children[1]));
-
+                if (children[0].GetKind() ==BEEV::BVAND && children[0].Degree() > 1 && ((children[0][0] == children[1]) || children[0][1] == children[1]))
+                    result = ASTFalse;
                break;
 
        case BEEV::BVGE: