From 9b137d54d34e0a014b4c5c5c9c21cbf43b78f604 Mon Sep 17 00:00:00 2001
From: "Christoph M. Wintersteiger" <cwinter@microsoft.com>
Date: Wed, 18 Feb 2015 16:25:27 +0000
Subject: [PATCH] Bugfix and new examples for implicit assumptions in
Z3_solver_assert_and_track. Thanks to Amir Ebrahimi for reporting this issue!
(See
http://stackoverflow.com/questions/28558683/modeling-constraints-in-z3-and-unsat-core-cases)
Signed-off-by: Christoph M. Wintersteiger <cwinter@microsoft.com>
---
examples/dotnet/Program.cs | 42 ++++++++++++++++++++++++++++++++++
examples/java/JavaExample.java | 42 ++++++++++++++++++++++++++++++++++
src/solver/combined_solver.cpp | 15 ++++++++++--
src/solver/solver.h | 12 +++++++++-
src/solver/solver_na2as.h | 3 +++
5 files changed, 111 insertions(+), 3 deletions(-)
diff --git a/examples/dotnet/Program.cs b/examples/dotnet/Program.cs
index 0847bc868..e1b5fb6d8 100644
--- a/examples/dotnet/Program.cs
+++ b/examples/dotnet/Program.cs
@@ -2010,6 +2010,47 @@ namespace test_mapi
}
}
+ /// <summary>
+ /// Extract unsatisfiable core example with AssertAndTrack
+ /// </summary>
+ public static void UnsatCoreAndProofExample2(Context ctx)
+ {
+ Console.WriteLine("UnsatCoreAndProofExample2");
+
+ Solver solver = ctx.MkSolver();
+
+ BoolExpr pa = ctx.MkBoolConst("PredA");
+ BoolExpr pb = ctx.MkBoolConst("PredB");
+ BoolExpr pc = ctx.MkBoolConst("PredC");
+ BoolExpr pd = ctx.MkBoolConst("PredD");
+
+ BoolExpr f1 = ctx.MkAnd(new BoolExpr[] { pa, pb, pc });
+ BoolExpr f2 = ctx.MkAnd(new BoolExpr[] { pa, ctx.MkNot(pb), pc });
+ BoolExpr f3 = ctx.MkOr(ctx.MkNot(pa), ctx.MkNot(pc));
+ BoolExpr f4 = pd;
+
+ BoolExpr p1 = ctx.MkBoolConst("P1");
+ BoolExpr p2 = ctx.MkBoolConst("P2");
+ BoolExpr p3 = ctx.MkBoolConst("P3");
+ BoolExpr p4 = ctx.MkBoolConst("P4");
+
+ solver.AssertAndTrack(f1, p1);
+ solver.AssertAndTrack(f2, p2);
+ solver.AssertAndTrack(f3, p3);
+ solver.AssertAndTrack(f4, p4);
+ Status result = solver.Check();
+
+ if (result == Status.UNSATISFIABLE)
+ {
+ Console.WriteLine("unsat");
+ Console.WriteLine("core: ");
+ foreach (Expr c in solver.UnsatCore)
+ {
+ Console.WriteLine("{0}", c);
+ }
+ }
+ }
+
public static void FiniteDomainExample(Context ctx)
{
Console.WriteLine("FiniteDomainExample");
@@ -2164,6 +2205,7 @@ namespace test_mapi
TreeExample(ctx);
ForestExample(ctx);
UnsatCoreAndProofExample(ctx);
+ UnsatCoreAndProofExample2(ctx);
}
// These examples need proof generation turned on and auto-config set to false.
diff --git a/examples/java/JavaExample.java b/examples/java/JavaExample.java
index d23f249de..5c49b56ae 100644
--- a/examples/java/JavaExample.java
+++ b/examples/java/JavaExample.java
@@ -2137,6 +2137,47 @@ class JavaExample
}
}
}
+
+ /// Extract unsatisfiable core example with AssertAndTrack
+
+ public void unsatCoreAndProofExample2(Context ctx) throws Z3Exception
+ {
+ System.out.println("UnsatCoreAndProofExample2");
+ Log.append("UnsatCoreAndProofExample2");
+
+ Solver solver = ctx.mkSolver();
+
+ BoolExpr pa = ctx.mkBoolConst("PredA");
+ BoolExpr pb = ctx.mkBoolConst("PredB");
+ BoolExpr pc = ctx.mkBoolConst("PredC");
+ BoolExpr pd = ctx.mkBoolConst("PredD");
+
+ BoolExpr f1 = ctx.mkAnd(new BoolExpr[] { pa, pb, pc });
+ BoolExpr f2 = ctx.mkAnd(new BoolExpr[] { pa, ctx.mkNot(pb), pc });
+ BoolExpr f3 = ctx.mkOr(ctx.mkNot(pa), ctx.mkNot(pc));
+ BoolExpr f4 = pd;
+
+ BoolExpr p1 = ctx.mkBoolConst("P1");
+ BoolExpr p2 = ctx.mkBoolConst("P2");
+ BoolExpr p3 = ctx.mkBoolConst("P3");
+ BoolExpr p4 = ctx.mkBoolConst("P4");
+
+ solver.assertAndTrack(f1, p1);
+ solver.assertAndTrack(f2, p2);
+ solver.assertAndTrack(f3, p3);
+ solver.assertAndTrack(f4, p4);
+ Status result = solver.check();
+
+ if (result == Status.UNSATISFIABLE)
+ {
+ System.out.println("unsat");
+ System.out.println("core: ");
+ for (Expr c : solver.getUnsatCore())
+ {
+ System.out.println(c);
+ }
+ }
+ }
public void finiteDomainExample(Context ctx) throws Z3Exception
{
@@ -2298,6 +2339,7 @@ class JavaExample
p.treeExample(ctx);
p.forestExample(ctx);
p.unsatCoreAndProofExample(ctx);
+ p.unsatCoreAndProofExample2(ctx);
}
{ // These examples need proof generation turned on and auto-config
diff --git a/src/solver/combined_solver.cpp b/src/solver/combined_solver.cpp
index dfbb62f65..649a79be2 100644
--- a/src/solver/combined_solver.cpp
+++ b/src/solver/combined_solver.cpp
@@ -178,8 +178,9 @@ public:
virtual lbool check_sat(unsigned num_assumptions, expr * const * assumptions) {
m_check_sat_executed = true;
-
- if (num_assumptions > 0 || // assumptions were provided
+
+ if (get_num_assumptions() != 0 ||
+ num_assumptions > 0 || // assumptions were provided
m_ignore_solver1) {
// must use incremental solver
switch_inc_mode();
@@ -241,6 +242,16 @@ public:
return m_solver1->get_assertion(idx);
}
+ virtual unsigned get_num_assumptions() const {
+ return m_solver1->get_num_assumptions() + m_solver2->get_num_assumptions();
+ }
+
+ virtual expr * get_assumption(unsigned idx) const {
+ unsigned c1 = m_solver1->get_num_assumptions();
+ if (idx < c1) return m_solver1->get_assumption(idx);
+ return m_solver2->get_assumption(idx - c1);
+ }
+
virtual void display(std::ostream & out) const {
m_solver1->display(out);
}
diff --git a/src/solver/solver.h b/src/solver/solver.h
index a95c649c0..b5a407e2a 100644
--- a/src/solver/solver.h
+++ b/src/solver/solver.h
@@ -72,7 +72,7 @@ public:
/**
\brief Add a new formula \c t to the assertion stack, and "tag" it with \c a.
- The propositional varialbe \c a is used to track the use of \c t in a proof
+ The propositional variable \c a is used to track the use of \c t in a proof
of unsatisfiability.
*/
virtual void assert_expr(expr * t, expr * a) = 0;
@@ -125,6 +125,16 @@ public:
*/
virtual expr * get_assertion(unsigned idx) const;
+ /**
+ \brief The number of tracked assumptions (see assert_expr(t, a)).
+ */
+ virtual unsigned get_num_assumptions() const = 0;
+
+ /**
+ \brief Retrieves the idx'th tracked assumption (see assert_expr(t, a)).
+ */
+ virtual expr * get_assumption(unsigned idx) const = 0;
+
/**
\brief Display the content of this solver.
*/
diff --git a/src/solver/solver_na2as.h b/src/solver/solver_na2as.h
index 15750344a..4c6af0dca 100644
--- a/src/solver/solver_na2as.h
+++ b/src/solver/solver_na2as.h
@@ -41,6 +41,9 @@ public:
virtual void push();
virtual void pop(unsigned n);
virtual unsigned get_scope_level() const;
+
+ virtual unsigned get_num_assumptions() const { return m_assumptions.size(); }
+ virtual expr * get_assumption(unsigned idx) const { return m_assumptions[idx]; }
protected:
virtual lbool check_sat_core(unsigned num_assumptions, expr * const * assumptions) = 0;
virtual void push_core() = 0;