z3py

问题 I need to solve this code (the code in C) if ( ((0xAAAAAAAAAAAAAAABLL * len_input_serial >> 64) >> 1)+ len_input_serial- 3 * ((0xAAAAAAAAAAAAAAABLL * len_input_serial >> 64) >> 1) != 14) return 0xFFFFFFFFLL; that's my python script from z3 import * len_input_serial = BitVec("serial_len",64) solve(LShR(LShR(0xAAAAAAAAAAAAAAABL * len_input_serial,64),1) + len_input_serial - 3 * LShR(LShR(0xAAAAAAAAAAAAAAABL * len_input_serial,64),1) == 14) However this gives me [serial_len = 14] I know the

问题 I installed the Z3 theorem prover on Linux, and am using its Python bindings (Z3Py). I tried to test a minimal example, but I immediately got the following error: z3.z3types.Z3Exception: init(Z3_LIBRARY_PATH) must be invoked before using Z3-python How do I fix this and get up and running with Z3? I'm not quite sure what that error message means. The Z3 documentation and tutorials don't seem to say anything about this or about init() , and the Z3-Python docs don't list any function called init

问题 I would like to use Z3 to optimize a set of equations. The problem hereby is my equations are non-linear but most importantly they do have trigonometric functions. Is there a way to deal with that in z3? I am using the z3py API. 回答1: Transcendental numbers and trigonometric functions are usually not supported by SMT solvers. As Christopher pointed out (thanks!), Z3 does have support for trigonometric functions and transcendentals; but the support is rather quite limited. (In practice, this

问题 I am very new to z3py. I am trying to code the following logarithmic expressions in z3py . log(x,y) I did search stack overflow a lot and came across a similar question, but unfortunately I could not get a satisfactory enough answer. Please help me! 回答1: More generally, how can we define logs with Z3? The only way I have gotten any traction at all is to use an approximate value for e , define exp(x) as (^ e x) , and then define log as a total function that is the inverse of exp . In SMT-LIB 2

问题 So basically I am trying to solve the following SMT constraint with a generic constraint solver like Z3: >>> from z3 import * >>> a = BitVec("a", 32) >>> b = BitVec("b", 32) >>> c1 = (a + 32) & (b & 0xff) >>> c2 = (b & 0xff) >>> s = Solver() >>> s.add(c1 == c2) >>> s.check() sat >>> s.model() [b = 0, a = 4294967199] Note that obviously, the constraint should be sat whenever b falls within the range of [0x00000000, 0xffffff00] . So here is my question, is it in general feasible for a SMT

问题 I am trying to perform some symbolic calculation on matrices (with symbols as an entries of matrices), and after that I will have a number of possible solution. My goal is to select solutions/ solution based upon constraints. for example, M is a matrix which have one element as a symbol . This matrix will have 2 eigenvalues one is positive an one is negative. Using z3 I am trying to find out only negative value, but I am unable to do so as a is defined as a symbol and I cannot write it as a

问题 Given 2 equations c == a + 4 and t == c + b , if a == -4 , then t == b . I am trying to do the opposite, meaning given the above 2 equations, and t == b , I try to find value of a . I have below code to do this with ForAll and Implies : from z3 import * a, b, c, t = BitVecs('a b c t', 32) g = True g = And(g, c == (a + 4)) g = And(g, t == (c + b)) s = Solver() s.add(ForAll([c, t, b], Implies(g, t == b))) if s.check() == sat: print s.model()[a] else: print 'Unsat' However, running the above

问题 I am trying to count the number of satisfying assignments by Z3. I am wondering if Z3 provides such information. If so, how can I count models in Z3 and particularly in Z3Py? 回答1: While Taylor's answer will give you the number of satisfying assignments, it will iterate over all of them. In principle, it is possible to do it without such an expensive iteration, but Z3 does not offer it. There are efficient model counters for propositional logic, the same language used in SAT (search for

问题 rise4fun z3py is unavailable from several weeks due to some security issues. I tried to find out some resources for learning z3py but ended in vain. Please suggest some resources to learn z3py 回答1: I created a zip file with the Z3Py tutorials sources. It is basically a few HTML pages and a bunch of python files. Here is the link: https://github.com/leodemoura/leodemoura.github.com/blob/master/files/z3py.zip?raw=true Update (Jan 14, 2014) : the Z3Py tutorials are back online 回答2: The official

问题 Over the years I keep track of solving technology - and I maintain a blog post about applying them to a specific puzzle - the "crossing ladders". To get to the point, I accidentally found out about z3, and tried putting it to use in the specific problem. I used the Python bindings, and wrote this: $ cat laddersZ3.py #!/usr/bin/env python from z3 import * a = Int('a') b = Int('b') c = Int('c') d = Int('d') e = Int('e') f = Int('f') solve( a>0, a<200, b>0, b<200, c>0, c<200, d>0, d<200, e>0, e