Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [model-checking]

Model checking refers to the following problem: given a model of a system, test automatically whether this model meets a given specification.

4
votes
1answer
39 views

Is model checking PSpace-hard *in formula size*?

Sistla/Clarke proved [SC82] that the LTL model-checking problem is PSpace-complete. Sometimes people write that this problem is "PSpace-hard in $|\phi|$" (e.g. [LP85]). What does this mean formally? ...
4
votes
1answer
44 views

Are two CCS processes equivalent with respect to weak bisimilarity if and only if they satisfy exactly the same set of HML formulas?

I was skimming this recent paper and I was struck by the following statement: two processes are equivalent with respect to weak bisimilarity if and only if they satisfy exactly the same set of HML ...
2
votes
1answer
70 views

Negation of the semantics of the Until operator in LTL

I have been looking at the Until operator and the release operator and when introduced to the release operator it was suggested that it is equivalent to: $\phi R \psi \equiv \neg(\neg\phi U \neg \psi)...
1
vote
2answers
43 views

(Generally) How to specify asynchronous action with side effects using logic equations

Say you have this function call sequence: function all() { fn1() fn2() fn3() } And say that fn2 was asynchronous and ...
1
vote
2answers
88 views

Buchi automata in formal software verification

As I am studying the application of Buchi automata in formal software verification, I am interested in the computational complexity (or links to papers) for the algorithms used to solve the problem in ...
0
votes
1answer
40 views

Model Checking CTL* algorithm

Currently I'm trying to understand the CTL* model checking algorithm from this book. The basic idea is clear to that we can use the LTL algorithm to whenever we have a subformular $E\phi$ or $A\phi$ ...
1
vote
1answer
46 views

Validity of CTL formula $s_0 \models EG\ AF\ p$ in given model

I have been learning Verification by model checking recently and I get the following question: Is the CTL formula $s_{0} \models EG\ AF\ p$ valid in the following model? I think it is ...
1
vote
1answer
32 views

How to prove a LTL formula correct in a specific model?

I have been learning Verification by model checking recently and I get the following question: $Whether\ the\ LTL\ formula\ M, q_3\ \models (X\ \lnot a) \rightarrow (F\ G\ \lnot a)\ is\ established\ ...
0
votes
0answers
12 views

Timed Kripke structures with inequality constraints

I am having problems creating a timed Kripke structure $\mathcal{TK} = \langle S, \mathcal{T}, \rightarrow, L \rangle$ for a system that I have. My system, a timed automaton system (time base $\...
2
votes
1answer
43 views

How do you correctly write this sentence as a CTL formula?

Sentence: From every reachable state it is possible to reach a state where $p$ is true. How do you write this sentence as a CTL formula? So far I only dealt with CTL syntax and trees but maybe it ...
2
votes
2answers
80 views

How to express the existence of winning strategy of the starter of a game in temporal logic?

Consider a two-player game. A winning strategy of a player is a strategy following which the player can always beat his opponent, no matter how his opponent responds. A game can be unfolded to a ...
0
votes
1answer
39 views

How to collect all states of a behavior in TLA+?

Description of the problem: I am modeling checking a distributed protocol against a global property with TLA+ developed by Leslie Lamport. The global property is defined on all states of a behavior (...
1
vote
0answers
32 views

How Model Checking works with User Interaction

In order to understand how to apply Model Checking, I am wondering how to apply it to a pseudo-realistic async program. Say I have the following pseudocode: ...
1
vote
1answer
109 views

How to define the Atomic Propositions in Model Checking

The atomic propositions in Symbolic Model Checking form the state in the state-transition graph (the model $\mathcal{M}$ in Model Checking). The other part of Model Checking is the specification, ...
0
votes
0answers
50 views

How to combine Symbolic Model Checking with Symbolic Execution

I have started reading some textbooks and papers on Model Checking, and have run into the closely related but different Symbolic Execution. I have a few open questions on StackOverflow about the "...
2
votes
1answer
60 views

What exactly state is in Model Checking

So I finally realized the difference between transition systems and automata, and now am closer to understanding Model Checking. One of the last pieces is understanding what exactly "state" is in ...
2
votes
1answer
144 views

Least fix point of CTL formula

In the book Logic in Computer Science on page 244, there is a proof that $[[E(\phi U\psi)]]$ is the least fixed point of $G(X)=[[\psi]] \cup ([[\phi]]\cap\mathop{\textrm{pre}}_\exists(X))$. I don't ...
4
votes
1answer
181 views

How does TLC check liveness properties?

The paper "Model Checking TLA+ Specifications" published in 1999 explained how TLC (Temporal Logic Checker) checks safety properties written in TLA+ developed by Lamport. At that time, TLC did not yet ...
1
vote
0answers
33 views

CTL satisfied by Kripke Structure

given a Kripke Structure I want to check if a CTL formula is satisfied or not. the CTL is: $$ AG(c \vee AX\neg E((a\vee b)Uc)) $$ I have read that it is better to write to CTL in terms of $\wedge $ ...
1
vote
0answers
37 views
1
vote
0answers
49 views

Understanding a Single Step in the Model Checking Algorithm

This answer explains roughly how to convert a nested boolean function into a Binary Decision Diagram (BDD). This question is about how to structure the states for the BDD. Now in this question I am ...
2
votes
0answers
130 views

Equivalence preserving operator from CTL* to LTL

The question is about an operator that transforms any CTL* formula ${\psi}$ into a (not necessarily equivalent) LTL formula ${A\psi^d}$, where $d$ means syntactically removing all $A,E$ quantifiers ...
1
vote
2answers
47 views

How to prove a side effect in a function

I asked a question earlier about Saving to the Database, which was very general and about the requirements for a proof when you go through many layers of non-verified systems such as the network and ...
0
votes
1answer
42 views

What the State is, and Where it comes from, when Generating Reachability Graphs

For Timed Automata, I found Figure 1 below. For Coloured Petri Nets I found Figure 2. Both are for "Reachability Graph Construction". However, they don't describe where they got the states from (...
2
votes
1answer
46 views

Acceptance conditions when translating LTL to Büchi automaton?

As an exercise in better understanding, I have been implementing the LTL to Generalized Büchi Automaton translation algorithm of Gerth, et al. (which is also discussed in Clarke, et al., Model ...
2
votes
0answers
46 views

Why do we have free variables in mu-calculus?

I'm reading the Model Chekcing book of E. M. Clarke and in the chapter about µ-calculus there is an example formula $$ f = \mu Z. ((q \mathrel{\mathrm{AND}} Y) \mathrel{\mathrm{OR}} \langle a \rangle ...
0
votes
0answers
41 views

Create a transition system where every sequence has at least twice as many $a$'s than $b$'s

Create a transition system with edges $a$ and $b$ and an initial state, such that for all possible sequences, you have that: The amount of $a$'s in the sequence is at least twice as much as the ...
1
vote
1answer
176 views

Explanation of the Gelfond Lifschitz reduct

Can someone explain with a hands on example how the Gelfond Lifschitz reduct works in order to check stable model semantics? edit a simple example here - at least as far as I understand the thing. ...
0
votes
1answer
63 views

Given two formulae E[G F p] (which is CTL*) and EG EF p ( which is a CTL) with a Model prove that they are not equivalent

I am trying to prove they are not equivalent , a model which satisfies the fist one but not the second since I think EG EF p is stronger than E[GF p],any leads would be helpful. Thanks.
0
votes
1answer
33 views

Finding Models for a sequent

I am trying to generate models for the following sequent. $$\exists x \exists y \forall z (z = x \lor z = y)$$ What I have come up with is this. $$A= \{0,1\}$$ So in this model, for all the values ...
0
votes
1answer
85 views

LTL to GBA versus LTL to BA

Let's assume that I have an LTL formula and I want to convert it to a Buchi automaton. For which fragment of LTL, GBA is more succinct and for which fragment BA has the same size as GBA.
1
vote
0answers
71 views

Importance of Needham–Schroeder Protocol

I'm working on a paper about model checking on cryptographic protocols and many of the papers I have read, base their approaches in the Needham-Schroeder protocol. I undestand this was one of the ...
1
vote
0answers
86 views

Calculate expected values of “Craps Game” with the help of Prism Model Checker

I have modelled the craps game (https://en.wikipedia.org/wiki/Craps#Rules_of_play) as a dtmc with the prism model checker: ...
3
votes
1answer
90 views

CTL* query evaluation order

I'm currently trying to evaluate a CTL* expression and am not sure how to stepwisely evaluate the queries. For example I have EFG p. This means something like 'there is a path where eventually there ...
4
votes
0answers
43 views

How the $EX(f)$ is evaluated in symbolic model checking?

I was reading the symbolic model checking, So there it has mentioned that we can represent the set of states and transition relations of any transition system with the help of ROBDDs. I was trying to ...
11
votes
1answer
147 views

Programming language semantics prototyping tool

Is there any tool for prototyping a programming language semantics and type system and that also allows for some sort of model checking of standard properties, like type soundness? I'm asking this, ...
2
votes
1answer
230 views

Modeling a sequential circuit as a transition system

I was asked to model the following sequential circuits C1, C2 as transition systems (i.e. identify the output y function and register functions r1, r2, r3) For C2 there appears to be not input x and ...
1
vote
0answers
94 views

generic technique to build LTL/CTL formula that satisfy specific inputs to a model

I have an automaton, for example the below automaton and would like to generate a single formula (LTL or CTL, or some other representation) that satisfy exactly the traces provided. e.g., $t_1 = i^*...
1
vote
1answer
149 views

How to verify a property about a certain order of events in TCTL / UPPAAL?

I'd like to check if a certain order of events happens if another property holds true using UPPAAL and TCTL. ...
1
vote
1answer
84 views

Can QBF encode #QBF?

In another question Initializing non-deterministic variables in QBF, I was interested about translating assertion-based pseudocode to QBF in order to have an exponentially more compact encoding ...
1
vote
1answer
82 views

Initializing non-deterministic variables in QBF

I'm trying to translate the following pseudocode to QBF. The integers are encoded as simple fixed-width bitvectors, and the entire procedure runs in polynomial space ensuring QBF has enough ...
2
votes
1answer
118 views

What's the definition of ACTL?

I have been looking for the definition of ACTL, but Google has given me very little to go with. So far, I know ACTL is another form of CTL model checking, and CTL includes the following operators: ...
0
votes
1answer
361 views

How to prove LTL-formulas true for all paths?

I'm quoting a question from my homework which I don't understand its wording. Also, I'm not looking for an answer for my problem, I just want to be pointed at some articles/tutorials/reading/tips to ...
5
votes
1answer
131 views

The importance of the language semantics for code generation and frameworks for code generation in model-driven development

I am implementing worflow where the code in industrial programming languages (JavaScript and Java) should be generated from the formal (formally verified) expressions (from ontologies as objects and ...
2
votes
1answer
338 views

LTL properties in bounded model checking via assertions

Is there a way to check LTL properties in a bounded model checker? As an example, consider a liveness property ($G F p$ - always eventually $p$)? Suppose we have the following trivial program ...
2
votes
1answer
423 views

The Interleaved Transition System for 2 Independent and Concurrent Transition Systems

This question is about Model Checking for Software Formal Verification How do you model the joint behavior of 2 independent and concurrent transition systems? Specifically, given the two independent ...
2
votes
1answer
193 views

What's a side-effect free expression in Timed Automata?

I'm trying to get myself more familiar with Timed Automata theory. At some point I came across the expression "side-effect free" like in the following: A guard is a side-effect free expression that ...
0
votes
2answers
652 views

What does least fix point and greatest fix point mean in Safety games

In safety games there are these mathematical notation about greatest fix points and least fix points but I don't get it. How would we describe them plain English without mathematical symbols.
0
votes
1answer
150 views

Determining which states in a transition system satisfy a specific CTL formula [closed]

Trying to answer the following question: However, my answer is that only one of these states satisfy the TS (which is for sure wrong since the next part of this question asks to remove states that ...
1
vote
1answer
146 views

Find equivalent LTL formula, without Y (Yesterday) operator. How can I handle first state?

The task is to find an equivalent LTL formula for $G(a \Rightarrow Yb)$, which doesn't contain the Y operator. My idea is to search for invalid path patterns with 2 $a$'s in a row, e.g. bbbbaab. ...