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Questions tagged [z3]

Z3 is a high-performance theorem prover being developed at Microsoft Research.

Z3 is a high-performance theorem prover being developed at Microsoft Research. Z3 supports linear real and integer arithmetic, fixed-size bit-vectors, extensional arrays, uninterpreted functions, and quantifiers.

Some key features of Z3 are:

  • High-performance theorem prover
  • Integrating efficient constraint solving technologies
  • Checking satisfiability of logical formulas with quantifiers
  • Highly customizable with an extensive API
  • Including support for custom theories

For more information about Z3, visit the Z3 homepage or try Z3 in your browser.

See also Z3 tutorial guide for more in-depth introduction about Z3.

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Z3: Performing Matrix Operations

My Situation I'm working on a project which needs to: Prove the correctness of 3D matrix transformation formulas involving matrix operations Find a model with the values of the unknown matrix entries. My Question What's the best way to express…
fdj815
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z3 number of solutions

How do I use z3 to count the number of solutions? For example, I want to prove that for any n, there are 2 solutions to the set of equations {x^2 == 1, y_1 == 1, ..., y_n == 1}. The following code shows satisfiability for a given n, which isn't…
Alex Reece
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How to implement array of bitvectors in z3's Python APIs

I am new to z3py and was going through the Z3 API in Python, but couldn't figure out how to define an array of bitvectors. I want something like: DOT__mem[16] = BitVec('DOT__mem[16]', 8) but this syntax didn't work, even on the practice panel in…
Sharad
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retrieving value of an enumerated type in Z3Py

How do I retrieve the values of an enumerated variable v ? For example, vTyp, (val1,val2,val3) = EnumSort('vTyp',['val1','val2','val3']) v = Const('my variable',vTyp) Now, given just the above variable v, how would I retrieve a list of values …
Vu Nguyen
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z3 C++ API & ite

Maybe I missed something, but what is the way of constructing an if-then-else expression using the z3 C++ API ? I could use the C API for that, but I'm wondering why there is no such function in the C++ API. regards, Julien
Julien H.
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Bit-wise with Z3?

I write the following Z3 python code x, y = Ints('x y') F = (x == y & 16) # x has the value of (y & 16) print F But I get bellow error: TypeError: unsupported operand type(s) for &: 'instance' and 'int' How to do bitwise arithmetic (& in this…
user311703
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Learning Z3py - Is there support for arrays and loops

I'm going through Z3py and have a question with how to use the API in a couple specific cases. The code below is a simplified version of something I would ultimately like to use Z3 for. Some of my questions are: 1. Is there a way to create an…
daybreak
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Can Z3 be used to preprocess problems?

Doing new research on SMT solvers is many times hindered by the fact that the available problems require lots of tricks and pre-processing techniques not directly related to decision procedures. These are often unpublished or take time to implement…
Dejan Jovanović
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Z3 with Craig interpolation (iz3)

I'm trying to generate Craig interpolants using the C API but I get incorrect results. However, when I dump the same problem to a file via Z3_write_interpolation_problem and call iZ3 I get the expected interpolant. I attach the code to be able to…
user1854932
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prevent solution from being simplified

I want to the solution got back from z3 without simplification using let statements. For example if I give the following: (declare-const x Int) (elim-quantifiers (exists ((x.1 Int)) (and (or (and (= (- x.1 2) 0) (<= (- x.1 9) 0)) …
sriraj
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Empty model in z3

z3py snippet: x = Int('x') s = Solver() s.add(x <= x) print s.check() print s.model() print s.model().sexpr() http://rise4fun.com/Z3Py/mfPU Output: sat [] Any value of x would do but z3 returns empty model. Does a missing free variable x in the…
dips
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Z3 Performance with Non-Linear Arithmetic

We are running into performance problems with what I believe is the part of Z3 that treats non-linear arithmetic. Here is a simple concrete Boogie example, that when verified with Z3 (version 4.1) takes a long time (on the order of 3 minutes) to…
stefan
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z3 const declaration

In Z3 Python, what's the diff between 1) x = Const("x",IntSort()) vs 2) x = Int("x") ? is_const returns true for both and they are both ArithRef. I would thought 1) would be appropriate for defining a const, e.g., x is 3.14 and 2) is to…
Vu Nguyen
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TryFor in Z3 does not stop checking after the given timelimit

I am using the .NET API of Z3. When I instantiate a solver by calling: Solver s = ctx.MkSolver(ctx.TryFor(ctx.MkTactic("qflia"), TimeLimit)); and give it a TimeLimit of 60 seconds (60000 milliseconds) for some models the statement s.Check() does…
larsbeck
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what's the difference between "simplify" and "ctx-solver-simplify" in z3

since current version, there is some problem in "ctx-solver-simplify"like in the example http://rise4fun.com/Z3/CqRv z3 gives the wrong answer. I replace "ctx-solver-simplify" by "simplify" like http://rise4fun.com/Z3/x9X4 I am wondering, what's…
user1487718
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