Questions about the fixedpoint engine of the Z3 theorem prover.
Questions tagged [z3-fixedpoint]
20 questions
3
votes
0 answers
Backtracking using push/pop operation on z3 fixedpoint solver
When I try to use push and pop operations for backtracking on z3's fixedpoint solver via python api, "operation is not supported by engine" exception is thrown by the solver.
b = Bool('b')
a = Bool('a')
s =…
user2408329
- 75
- 7
3
votes
1 answer
How to get multiple constraints in Z3 Fixedpoint?
When running the fragment
(declare-rel mypred (Int Int))
(declare-var A Int)
(declare-var B Int)
(declare-var C Int)
(rule (mypred 1 0))
(rule (mypred 2 1))
(rule (mypred 3 2))
(rule (mypred 4 3))
(rule (mypred 5 4))
(rule (=> (and (mypred C B)…
ranma42
- 31
- 1
2
votes
0 answers
Array as a parameter to a relation in z3 fixedpoint solver
I am using array as a parameter to a relation in z3 fixedpoint solver. I am trying to get array value in the certificate which satisfies my query. When I run this on z3 it throws an error stating Uninterpreted 'a1' in A(#1,#0,#3).
Why is array…
user2408329
- 75
- 7
1
vote
0 answers
why z3 horn solver result is unknown and why this is the unknown reason
I am using z3 to do equivalence check. I try to use z3 horn solver to accelerate z3 solving time, and I met the following problem:
I would like to check whether two programs are the same or not. The logic of two programs is
P1: a2 = a1 + 2, where…
Qiongwen Xu
- 11
- 2
1
vote
1 answer
Why does Z3 return Unknown for these horn clauses
I am using Z3 to solve my horn clauses. In the body of Horn clauses uninterpreted predicates should be positive. However, I need negation of some of uninterpreted predicates.
I have seen some examples in which negation works fine. For instance Z3…
Zeinab Ganjei
- 123
- 1
- 9
1
vote
0 answers
Z3: combining optimization and fixedpoints
I can explain to whatever depth is necessary, but the long story short is that my project uses Z3's optimizer to find the maximal solution to what is effectively a SAT problem with weights associated to the boolean variables. Separately to that,…
Syzygy
- 1,754
- 1
- 9
- 12
1
vote
1 answer
Can we use ite expression in Z3 fixed-point query
I modified the edge and path example in the z3 fixed-point tutorial
(set-option :fixedpoint.engine datalog)
(define-sort s () (_ BitVec 3))
(declare-rel edge (s s))
(declare-rel path (s s))
(declare-var a s)
(declare-var b s)
(declare-var c…
Kaituo Li
- 347
- 3
- 7
1
vote
1 answer
muZ3: Non-deterministic recursive call
Is there a way to perform a recursive call non-deterministically in a muZ3 relation specification? Specifically, I want to translate a function like the following:
int foo(int x) {
...
if (*) y = foo(y);
...
}
to the muZ3 rule format.
Hinton
- 2,320
- 4
- 26
- 32
1
vote
1 answer
Z3 get-answer returns unsupported
I'm using the fixedpoint engine in Z3 to encode several universal horn formulas. The query turns out to be unsat. In Z3Py, using get_answer() returns the valuations to the uninterpreted relations. However, in the SMTLIB2 format, get-answer returns…
Suvam Mukherjee
- 27
- 5
1
vote
1 answer
how to get constraint of variables in Fixedpoint using z3?
I wish to get the constraint of the element in the fixedpoint phi, in the following example, the constraint should be c2<=c1+5.0, c1>=5.0 it should be how to realize it in Z3? Or is there any way to do it not using fixedpoint in Z3
(set-option…
user1487718
1
vote
1 answer
how to get constraint of variable in Fixedpoint using z3?
I wish to get the constraint of the element in the fixedpoint phi like d>=0.0, how to realize it in Z3?
(set-option :produce-models true)
(set-option :dl_engine 1)
(set-option :dl_pdr_use_farkas true)
(declare-var c Real)
(declare-var d…
user1487718
1
vote
1 answer
An error appears when running exist quantifier and fixedpoint Z3 in C#
I tried to use ctx.mkExist in the fixedpoint, howwever, it occurs error said "contains recursive predicate", I don't know why? and How to use ctx.MkExists in fixedpoint?For example:
exist (lamda real) that lamb>=0 AND inv(c,i) AND phi(c+lamb,i) …
user1487718
0
votes
1 answer
z3: Horn clauses / Fixedpoints over inductive datatypes
I'm trying to make assertions about program equivalence using z3's Fixedpoints, and I'm finding that any sort of recursion, even trivially decidable recursion, makes z3 totally choke. This z3py tutorial specifically calls out program simulation as a…
hjfreyer
- 539
- 3
- 11
0
votes
2 answers
Python Z3 API Query : Can we get a partial model using the z3 python API when solver returns unkown status
I am pretty sure it has something to do with the python API. Is there a way to get back a partial model from z3 even when the status is unknown?
I am trying to get a model out of z3 even when the status returns unknown result. It fails with raising…
Sumit Lahiri
- 505
- 6
- 13
0
votes
1 answer
What are the equivalent horn clauses to these clauses?
I am using Z3 and the extended SMT-LIB2 syntax to solve my horn clauses.
I know that head of a horn clause should be an uninterpreted predicate; but, I wonder how I should rewrite the following clauses to be a set of horn clauses.
(declare-rel inv…
Zeinab Ganjei
- 123
- 1
- 9