z3py

Why Z3Py does not provide all possible solutions

那年仲夏 提交于 2019-12-06 06:45:22
I ran into a problem where Z3Py does not enumerate all possible solutions for the given Boolean clauses. I was wondering if anyone knows why this is happening. Here is the code I use for the Z3Py. There are 5 booleans: 1 2 3 4 and 5. from z3 import * a,b,c,d,e = Bools('1 2 3 4 5') solver = Solver() solver.add(Or(Not(a), Not(b))) solver.add(Or(Not(b), Not(c))) solver.add(Or(Not(c), Not(d))) solver.add(Or(Not(d), Not(e))) while solver.check() == sat: model = solver.model() block = [] for declaration in model: constant = declaration() block.append(constant != model[declaration]) solver.append(Or

How to loop over array in Z3Py

淺唱寂寞╮ 提交于 2019-12-05 13:21:30
As part of a reverse engineering exercise, I'm trying to write a Z3 solver to find a username and password that satisfy the program below. This is especially tough because the z3py tutorial that everyone refers to (rise4fun) is down. #include <iostream> #include <string> using namespace std; int main() { string name, pass; cout << "Name: "; cin >> name; cout << "Pass: "; cin >> pass; int sum = 0; for (size_t i = 0; i < name.size(); i++) { char c = name[i]; if (c < 'A') { cout << "Lose: char is less than A" << endl; return 1; } if (c > 'Z') { sum += c - 32; } else { sum += c; } } int r1 =

Solving formulas in parallel with z3

怎甘沉沦 提交于 2019-12-05 10:52:32
Let's say I have a z3 solver with a certain number of asserted constraints that are satisfiable. Let S be a set of constraints, I would like to verify for every constraint in S whether the formula is still satisfiable when adding the constraint to the solver. This can be easily done sequentially in such a fashion: results = [] for constraint in S: solver.push() solver.add(constraint) results.append(solver.check() == z3.sat) solver.pop() print all(results) Now, I would like to parallelize this to speed things up, but I'm not sure how to do it properly with z3. Here is an attempt. Consider the

How to model signed integer with BitVector?

纵然是瞬间 提交于 2019-12-05 08:45:54
Suppose that a is an integer of 8-bit of value 254 . If a is a signed integer, it is actually considered -2 . In contrary, if a is unsigned, it remains 254 . I am trying to model this signed/unsigned integer problem with BitVector theory with Z3, but it seems BitVector doesnt allow this. Is this true? Then any idea on how to model this in Z3py? Thanks so much. Z3 has APIs for the signed and unsigned interpretations. For example, in the C API, Z3_mk_bvslt creates the signed less than, and Z3_mk_bvult the unsigned one. In Z3Py, we overloaded < , <= , ... using the signed ones. For creating, the

Z3/Python getting python values from model

你离开我真会死。 提交于 2019-12-04 10:35:23
问题 How can I get real python values from a Z3 model? E.g. p = Bool('p') x = Real('x') s = Solver() s.add(Or(x < 5, x > 10), Or(p, x**2 == 2), Not(p)) s.check() print s.model()[x] print s.model()[p] prints -1.4142135623? False but those are Z3 objects and not python float/bool objects. I know that I can check boolean values using is_true / is_false , but how can I elegantly convert ints/reals/... back to usable values (without going through strings and cutting away this extra ? symbol, for

Incremental solving in Z3 using push command

不想你离开。 提交于 2019-12-03 20:25:28
问题 I am using Z3's python api to do some kind of incremental solving. I push constraints to the solver iteratively while checking for unsatisfiability at each step using solver.push() command. I want to understand whether Z3 would use the learned lemmas from previous constraints or the satisfying solution previously obtained when solving with a newly added constraint. I never use the solver.pop() command. Where can I get more details about how the work done in previous iterations is used? 回答1:

how to get multiple solutions for z3 solver in smt2 format example?

北慕城南 提交于 2019-12-02 13:31:15
How to generate multiple models for bit vector formula using z3 solver in smt2 format? While implementing IDEA Code for Bit Vector it is generating one model. How to generate all possible models for the same if exists? ex.smt2 file (set-logic QF_BV) (set-info :smt-lib-version 2.0) (declare-const A0 (_ BitVec 16)) (declare-const A1 (_ BitVec 16)) (declare-const A2 (_ BitVec 16)) (declare-const B0 (_ BitVec 16)) (declare-const B1 (_ BitVec 16)) (declare-const B2 (_ BitVec 16)) (declare-const C0 (_ BitVec 16)) (declare-const C1 (_ BitVec 16)) (declare-const C2 (_ BitVec 16)) (declare-const D0 (_

Z3 randomness of generated model values

喜欢而已 提交于 2019-12-02 13:23:14
问题 I'm trying to influence the randomness of results for model values generated by Z3. As far as I understand, the options for this are very limited: in case of linear arithmetic, the simplex solver does not allow for random results that still satisfy the given constraints. However, there is an option smt.arith.random_initial_value ("use random initial values in the simplex-based procedure for linear arithmetic (default: false)") which I don't seem to get working: from z3 import * set_option(

Nonzero vector in quantifier

▼魔方 西西 提交于 2019-12-02 08:03:42
问题 I want to verify a formula of the form: Exists p . ForAll x != 0 . f(x, p) > 0 An implementation (that isn't working) is the following: def f0(x0, x1, x, y): return x1 ** 2 * y + x0 ** 2 * x s = Solver() x0, x1 = Reals('x0 x1') p0, p1 = Reals('p0 p1') s.add(Exists([p0, p1], ForAll([x0, x1], f0(x0, x1, p0, p1) > 0 ) )) #s.add(Or(x0 != 0, x1 != 0)) while s.check() == sat: m = s.model() m.evaluate(x0, model_completion=True) m.evaluate(x1, model_completion=True) m.evaluate(p0, model_completion

Z3 randomness of generated model values

时光总嘲笑我的痴心妄想 提交于 2019-12-02 06:29:51
I'm trying to influence the randomness of results for model values generated by Z3. As far as I understand, the options for this are very limited: in case of linear arithmetic, the simplex solver does not allow for random results that still satisfy the given constraints. However, there is an option smt.arith.random_initial_value ("use random initial values in the simplex-based procedure for linear arithmetic (default: false)") which I don't seem to get working: from z3 import * set_option('smt.arith.random_initial_value',True) x = Int('x') y = Int('y') s = Solver() s.add( x+y > 0) s.check() s