Merge branch 'unstable' of https://git01.codeplex.com/z3 into unstable

src/duality/duality.h

@@ -1152,6 +1152,13 @@ protected:
 
       virtual void LearnFrom(Solver *old_solver) = 0;
 
+      /** Return true if the solution be incorrect due to recursion bounding.
+	  That is, the returned "solution" might contain all derivable facts up to the
+	  given recursion bound, but not be actually a fixed point.
+       */
+
+      virtual bool IsResultRecursionBounded() = 0;
+
       virtual ~Solver(){}
 
       static Solver *Create(const std::string &solver_class, RPFP *rpfp);

src/duality/duality_solver.cpp

@@ -768,6 +768,29 @@ namespace Duality {
       annot.Simplify();
     }    
 
+    bool recursionBounded;
+
+    /** See if the solution might be bounded. */
+    void TestRecursionBounded(){
+      recursionBounded = false;
+      if(RecursionBound == -1)
+	return;
+      for(unsigned i = 0; i < nodes.size(); i++){
+	Node *node = nodes[i];
+	std::vector<Node *> &insts = insts_of_node[node];
+	for(unsigned j = 0; j < insts.size(); j++)
+	  if(indset->Contains(insts[j]))
+	    if(NodePastRecursionBound(insts[j])){
+	      recursionBounded = true;
+	      return;
+	    }
+      }
+    }    
+
+    bool IsResultRecursionBounded(){
+      return recursionBounded;
+    }
+
     /** Generate a proposed solution of the input RPFP from
 	the unwinding, by unioning the instances of each node. */
     void GenSolutionFromIndSet(bool with_markers = false){
@@ -1026,6 +1049,7 @@ namespace Duality {
 	timer_stop("ProduceCandidatesForExtension");
 	if(candidates.empty()){
 	  GenSolutionFromIndSet();
+	  TestRecursionBounded();
 	  return true;
 	}
 	Candidate cand = candidates.front();

src/muz/base/dl_context.h

@@ -53,6 +53,7 @@ namespace datalog {
         MEMOUT,
         INPUT_ERROR,
         APPROX,
+	BOUNDED,
         CANCELED
     };
 
@@ -304,6 +305,8 @@ namespace datalog {
            \brief Retrieve predicates
         */
         func_decl_set const& get_predicates() const { return m_preds; }
+	ast_ref_vector const &get_pinned() const {return m_pinned; }
+
         bool is_predicate(func_decl* pred) const { return m_preds.contains(pred); }
         bool is_predicate(expr * e) const { return is_app(e) && is_predicate(to_app(e)->get_decl()); }
 

src/muz/duality/duality_dl_interface.cpp

@@ -36,6 +36,7 @@ Revision History:
 #include "model_v2_pp.h"
 #include "fixedpoint_params.hpp"
 #include "used_vars.h"
+#include "func_decl_dependencies.h"
 
 // template class symbol_table<family_id>;
 
@@ -207,6 +208,46 @@ lbool dl_interface::query(::expr * query) {
     _d->rpfp->AssertAxiom(e);
   }
   
+  // make sure each predicate is the head of at least one clause
+  func_decl_set heads;
+  for(unsigned i = 0; i < clauses.size(); i++){
+    expr cl = clauses[i];
+
+    while(true){
+      if(cl.is_app()){
+	decl_kind k = cl.decl().get_decl_kind();
+	if(k == Implies)
+	  cl = cl.arg(1);
+	else {
+	  heads.insert(cl.decl());
+	  break;
+	}
+      }
+      else if(cl.is_quantifier())
+	cl = cl.body();
+      else break;
+    }
+  }
+  ast_ref_vector const &pinned = m_ctx.get_pinned();
+  for(unsigned i = 0; i < pinned.size(); i++){
+    ::ast *fa = pinned[i];
+    if(is_func_decl(fa)){
+      ::func_decl *fd = to_func_decl(fa);
+      if(m_ctx.is_predicate(fd)) {
+	func_decl f(_d->ctx,fd);
+	if(!heads.contains(fd)){
+	  int arity = f.arity();
+	  std::vector<expr> args;
+	  for(int j = 0; j < arity; j++)
+	    args.push_back(_d->ctx.fresh_func_decl("X",f.domain(j))());
+	  expr c = implies(_d->ctx.bool_val(false),f(args));
+	  c = _d->ctx.make_quant(Forall,args,c);
+	  clauses.push_back(c);
+	}
+      }
+    }
+  }
+
   // creates 1-1 map between clauses and rpfp edges
   _d->rpfp->FromClauses(clauses);
 
@@ -265,7 +306,19 @@ lbool dl_interface::query(::expr * query) {
   // dealloc(rs); this is now owned by data
 
   // true means the RPFP problem is SAT, so the query is UNSAT
-  return ans ? l_false : l_true;
+  // but we return undef if the UNSAT result is bounded
+  if(ans){
+    if(rs->IsResultRecursionBounded()){
+#if 0
+      m_ctx.set_status(datalog::BOUNDED);
+      return l_undef;
+#else
+      return l_false;
+#endif
+    }
+    return l_false;
+  }
+  return l_true;
 }
 
 expr_ref dl_interface::get_cover_delta(int level, ::func_decl* pred_orig) {

src/muz/fp/dl_cmds.cpp

@@ -252,6 +252,11 @@ public:
             print_certificate(ctx);
             break;
         case l_undef: 
+	    if(dlctx.get_status() == datalog::BOUNDED){
+	      ctx.regular_stream() << "bounded\n";
+	      print_certificate(ctx);
+	      break;
+	    }
             ctx.regular_stream() << "unknown\n";
             switch(dlctx.get_status()) {
             case datalog::INPUT_ERROR:

src/muz/pdr/pdr_context.cpp

@@ -736,6 +736,11 @@ namespace pdr {
         m_closed = true; 
     }
 
+    void model_node::reopen() {
+        SASSERT(m_closed);
+        m_closed = false;
+    }
+
     static bool is_ini(datalog::rule const& r) {
         return r.get_uninterpreted_tail_size() == 0;
     }
@@ -745,6 +750,7 @@ namespace pdr {
             return const_cast<datalog::rule*>(m_rule);
         }
         // only initial states are not set by the PDR search.
+        SASSERT(m_model.get());
         datalog::rule const& rl1 = pt().find_rule(*m_model);
         if (is_ini(rl1)) {
             set_rule(&rl1);
@@ -864,9 +870,10 @@ namespace pdr {
     }
 
     void model_search::add_leaf(model_node& n) {
-        unsigned& count = cache(n).insert_if_not_there2(n.state(), 0)->get_data().m_value;
-        ++count;
-        if (count == 1 || is_repeated(n)) {
+        model_nodes ns;
+        model_nodes& nodes = cache(n).insert_if_not_there2(n.state(), ns)->get_data().m_value;
+        nodes.push_back(&n);
+        if (nodes.size() == 1 || is_repeated(n)) {
             set_leaf(n);
         }
         else {
@@ -875,7 +882,7 @@ namespace pdr {
     }
 
     void model_search::set_leaf(model_node& n) {
-        erase_children(n);
+        erase_children(n, true);
         SASSERT(n.is_open());      
         enqueue_leaf(n);
     }
@@ -897,7 +904,7 @@ namespace pdr {
         set_leaf(*root);
     }
 
-    obj_map<expr, unsigned>& model_search::cache(model_node const& n) {
+    obj_map<expr, ptr_vector<model_node> >& model_search::cache(model_node const& n) {
         unsigned l = n.orig_level();
         if (l >= m_cache.size()) {
             m_cache.resize(l + 1);
@@ -905,7 +912,7 @@ namespace pdr {
         return m_cache[l];
     }
 
-    void model_search::erase_children(model_node& n) {
+    void model_search::erase_children(model_node& n, bool backtrack) {
         ptr_vector<model_node> todo, nodes;
         todo.append(n.children());
         erase_leaf(n);
@@ -916,13 +923,20 @@ namespace pdr {
             nodes.push_back(m);
             todo.append(m->children());
             erase_leaf(*m);
-            remove_node(*m);
+            remove_node(*m, backtrack);
         }
         std::for_each(nodes.begin(), nodes.end(), delete_proc<model_node>());
     }
 
-    void model_search::remove_node(model_node& n) {
-        if (0 == --cache(n).find(n.state())) {
+    void model_search::remove_node(model_node& n, bool backtrack) {
+        model_nodes& nodes = cache(n).find(n.state());
+        nodes.erase(&n);
+        if (nodes.size() > 0 && n.is_open() && backtrack) {
+            for (unsigned i = 0; i < nodes.size(); ++i) {
+                nodes[i]->reopen();
+            }
+        }
+        if (nodes.empty()) {            
             cache(n).remove(n.state());
         }
     }
@@ -1203,8 +1217,8 @@ namespace pdr {
 
     void model_search::reset() {
         if (m_root) {
-            erase_children(*m_root);
-            remove_node(*m_root);
+            erase_children(*m_root, false);
+            remove_node(*m_root, false);
             dealloc(m_root);
             m_root = 0;
         }
@@ -1240,7 +1254,7 @@ namespace pdr {
           m_pm(m_fparams, params.max_num_contexts(), m),
           m_query_pred(m),
           m_query(0),
-          m_search(m_params.bfs_model_search()),
+          m_search(m_params.bfs_model_search(), m),
           m_last_result(l_undef),
           m_inductive_lvl(0),
           m_expanded_lvl(0),

src/muz/pdr/pdr_context.h

@@ -231,6 +231,7 @@ namespace pdr {
         }
 
         void set_closed();     
+        void reopen();
         void set_pre_closed() { m_closed = true; }
         void reset() { m_children.reset(); }
 
@@ -243,19 +244,21 @@ namespace pdr {
     };
 
     class model_search {
+        typedef ptr_vector<model_node> model_nodes;
+        ast_manager&       m;
         bool               m_bfs;
         model_node*        m_root;
         std::deque<model_node*> m_leaves;
-        vector<obj_map<expr, unsigned> > m_cache;
+        vector<obj_map<expr, model_nodes > > m_cache;
         
-        obj_map<expr, unsigned>& cache(model_node const& n);
-        void erase_children(model_node& n);
+        obj_map<expr, model_nodes>& cache(model_node const& n);
+        void erase_children(model_node& n, bool backtrack);
         void erase_leaf(model_node& n);
-        void remove_node(model_node& n);
+        void remove_node(model_node& n, bool backtrack);
         void enqueue_leaf(model_node& n); // add leaf to priority queue.
         void update_models();
     public:
-        model_search(bool bfs): m_bfs(bfs), m_root(0) {}
+        model_search(bool bfs, ast_manager& m): m(m), m_bfs(bfs), m_root(0) {}
         ~model_search();
 
         void reset();