Z3 sources

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

lib/pdr_farkas_learner.h

@@ -0,0 +1,112 @@
+/*++
+Copyright (c) 2011 Microsoft Corporation
+
+Module Name:
+
+    pdr_farkas_learner.h
+
+Abstract:
+
+    SMT2 interface for the datalog PDR
+
+Author:
+
+    Krystof Hoder (t-khoder) 2011-11-1.
+
+Revision History:
+
+--*/
+
+#ifndef _PDR_FARKAS_LEARNER_H_
+#define _PDR_FARKAS_LEARNER_H_
+
+#include "arith_decl_plugin.h"
+#include "ast_translation.h"
+#include "bv_decl_plugin.h"
+#include "smt_solver.h"
+#include "pdr_manager.h"
+#include "bool_rewriter.h"
+#include "pdr_util.h"
+#include "front_end_params.h"
+#include "tactic.h"
+
+
+namespace pdr {
+
+class farkas_learner {
+    class farkas_collector;
+    class asserted_premise_collector;
+    class constant_replacer_cfg;
+    class equality_expander_cfg;
+    class constr;
+
+    typedef obj_hashtable<expr> expr_set;
+
+    front_end_params         m_proof_params;
+    ast_manager              m;
+    bool_rewriter            m_brwr;       /** bool rewriter for m_proof_mgr */
+    scoped_ptr<smt::solver>  m_ctx;
+    scoped_ptr<tactic>       m_simplifier;
+
+
+    static front_end_params get_proof_params(front_end_params& orig_params);
+
+    //
+    // all ast objects passed to private functions have m_proof_mgs as their ast_manager
+    //
+
+    ast_translation p2o;       /** Translate expression from inner ast_manager to outer one */
+    ast_translation o2p;       /** Translate expression from outer ast_manager to inner one */
+
+
+    /** All ast opbjects here are in the m_proof_mgs */
+    void get_lemma_guesses_internal(proof * p, expr* A, expr * B, expr_ref_vector& lemmas);
+
+    bool farkas2lemma(proof * fstep, expr* A, expr * B, expr_ref& res);
+
+    void combine_constraints(unsigned cnt, app * const * constrs, rational const * coeffs, expr_ref& res);
+
+    bool try_ensure_lemma_in_language(expr_ref& lemma, expr* A, const func_decl_set& lang);
+
+    bool is_farkas_lemma(expr* e);
+    
+    void get_lemmas(proof* root, expr_set const& bs, func_decl_set const& Bsymbs, expr* A, expr_ref_vector& lemmas);
+
+    void get_asserted(proof* p, expr_set const& bs, ast_mark& b_closed, expr_ref_vector& lemmas);
+
+    void permute_unit_resolution(proof_ref& pr);
+
+    void permute_unit_resolution(expr_ref_vector& refs, obj_map<proof,proof*>& cache, proof_ref& pr);
+
+    bool is_pure_expr(func_decl_set const& symbs, expr* e) const;
+
+    static void test();
+
+    void simplify_lemmas(expr_ref_vector& lemmas);
+
+public:
+    farkas_learner(front_end_params& params, ast_manager& m);
+
+    /**
+       All ast objects have the ast_manager which was passed as 
+       an argument to the constructor (i.e. m_outer_mgr)
+       
+       B is a conjunction of literals.
+       A && B is unsat, equivalently A => ~B is valid
+       Find a weakened B' such that
+       A && B' is unsat and B' uses vocabulary (and constants) in common with A.
+       return lemmas to weaken B.     
+    */
+
+    bool get_lemma_guesses(expr * A, expr * B, expr_ref_vector& lemmas);
+
+    void collect_statistics(statistics& st) const;
+
+    static void test(char const* filename);
+
+};
+
+
+}
+
+#endif