Představujeme vylepseni algoritmu, který překlada LTL formule na Buchiho automaty pomoci alternuj... more Představujeme vylepseni algoritmu, který překlada LTL formule na Buchiho automaty pomoci alternujicich automatů. Konkretněji zlepsujeme převod alternujicich Buchiho automatů na generalizovane Buchiho automaty, kde docasně ignorujeme některe přechody vedouci ze stavů alternujiciho automatu, ktere odpovidaji prefixově invariantnim formulim, což může vest k rychlejsimu překladu.
Překlad logiky linearniho casu (Linear Temporal Logic - LTL) na různe typy ɷ-automatů je intenziv... more Překlad logiky linearniho casu (Linear Temporal Logic - LTL) na různe typy ɷ-automatů je intenzivně studovana oblast, ktera ma mnoho aplikaci. Metoda LTL ověřovani modelu (LTL model checking) je rozsiřena a plně automatizovana technika, ktera se použiva k ověřeni, zda daný system splňuje požadovanou specifikaci. Jednim z klicových kroků je překlad logiky LTL na Buchiho automaty. Různe vlastnosti, jako velikost a determinismus použiteho automatu, mohou mit velký vliv na celkový výkon a průběh metody ověřovani modelu. Jine typy automatů, napřiklad deterministicke Rabinovy automaty, se použivaji při ověřovani modelu pravděpodobnostnich systemů. Překlad LTL na ɷ-automaty ma kromě metody ověřovani modelu využiti i v jiných oblastech jako jsou kontrola spravnosti (sanity checking), detekce prazdnosti (vacuity detection), synteza kontrolerů (controller synthesis) a synteza reaktivnich modulů (synthesis of reactive modules). Zlepseni různých překladů LTL na ɷ-automaty se v minulosti věnoval...
Some applications of linear temporal logic (LTL) require to translate formulae of the logic to de... more Some applications of linear temporal logic (LTL) require to translate formulae of the logic to deterministic ω-automata. There are currently two translators producing deterministic automata: ltl2dstar working for the whole LTL and Rabinizer applicable to LTL(F, G) which is the LTL fragment using only modalities F and G. We present a new translation to deterministic Rabin automata via alternating automata and deterministic transition-based generalized Rabin automata. Our translation applies to a fragment that is strictly larger than LTL(F, G). Experimental results show that our algorithm can produce significantly smaller automata compared to Rabinizer and ltl2dstar, especially for more complex LTL formulae.
Recently, there was defined a fragment of LTL (containing fairness properties among other interes... more Recently, there was defined a fragment of LTL (containing fairness properties among other interesting formulae) whose validity over a given infinite word depends only on an arbitrary suffix of the word. Building upon an existing translation from LTL to Büchi automata, we introduce a compositional approach where subformulae of this fragment are translated separately from the rest of an input formula and the produced automata are composed in a way that the subformulae are checked only in relevant accepting strongly connected components of the final automaton. Further, we suggest improvements over some procedures commonly applied to generalized Büchi automata, namely over generalized acceptance simplification and over degeneralization. Finally we show how existing simulation-based reductions can be implemented in a signature-based framework in a way that improves the determinism of the automaton.
Tools and Algorithms for the Construction and Analysis of Systems, 2012
We introduce improvements in the algorithm by Gastin and Oddoux translating LTL formulae into Büc... more We introduce improvements in the algorithm by Gastin and Oddoux translating LTL formulae into Büchi automata via very weak alternating co-Büchi automata and generalized Büchi automata. Several improvements are based on specific properties of any formula where each branch of its syntax tree contains at least one eventually operator and at least one always operator. These changes usually result in faster translations and smaller automata. Other improvements reduce non-determinism in the produced automata. In fact, we modified all the steps of the original algorithm and its implementation known as LTL2BA. Experimental results show that our modifications are real improvements. Their implementations within an LTL2BA translation made LTL2BA very competitive with the current version of SPOT, sometimes outperforming it substantially.
We identify a subtle error in LTL formulas reduction method used as one optimization step in an L... more We identify a subtle error in LTL formulas reduction method used as one optimization step in an LTL to B\"uchi automata translation. The error led to some incorrect answers of the established model checker DiVinE. This paper should help authors of other model checkers to avoid this error.
LTL overovanie modelu je siroko rozsirena a plne automatizovana technika, ktora sa použivana na o... more LTL overovanie modelu je siroko rozsirena a plne automatizovana technika, ktora sa použivana na overenie, ci daný system spĺňa požadovanu specifikaciu. Jedným z kľucových krokov je preklad logiky LTL na Buchiho automaty. Vlastnosti výsledneho automatu, ako su veľkosť a determinizmus, maju veľký vplyv na výkon celej procedury. Zlepseniu tohto prekladu sa už venovalo veľa usilia, napriek tomu maju dnesne prekladace stale ďaleko od dokonalosti. Cieľom dizertacnej prace je zlepsiť obecne preklad logiky LTL na ɷ-automaty s ohľadom na celkový výkon overovania modelu. V praxi sa vacsinou použivaju Buchiho automaty, preto sa v prvom rade chceme venovať zlepseniu tohto prekladu. V tezach prezentujeme niekoľko konkretnych vylepseni prekladu LTL na Buchiho automaty cez veľmi slabe alternujuce automaty. Najvýznamnejsim zlepsenim je takzvane odkladanie. V ďalsej faze nasej prace sa chceme venovať využitiu ostatných typov ɷ-automatov a zhodnotiť ich vplyv na celkový výkon procesu overovania model...
ABSTRACT Some applications of linear temporal logic (LTL) require to translate formulae of the lo... more ABSTRACT Some applications of linear temporal logic (LTL) require to translate formulae of the logic to deterministic omega-automata. There are currently two translators producing deterministic automata: ltl2dstar working for the whole LTL and Rabinizer applicable to LTL(F,G) which is the LTL fragment using only modalities F and G. We present a new translation to deterministic Rabin automata via alternating automata and deterministic transition-based generalized Rabin automata. Our translation applies to a fragment that is strictly larger than LTL(F,G). Experimental results show that our algorithm can produce significantly smaller automata compared to Rabinizer and ltl2dstar, especially for more complex LTL formulae.
Hereby I declare, that this thesis is my original authorial work, which I have worked out by my o... more Hereby I declare, that this thesis is my original authorial work, which I have worked out by my own. All sources, references and literature used or excerpted during elaboration of this work are properly cited and listed in complete reference to the due source.
ABSTRACT We introduce improvements in the algorithm by Gastin and Oddoux translating LTL formulae... more ABSTRACT We introduce improvements in the algorithm by Gastin and Oddoux translating LTL formulae into B\"uchi automata via very weak alternating co-B\"uchi automata and generalized B\"uchi automata. Several improvements are based on specific properties of any formula where each branch of its syntax tree contains at least one eventually operator and at least one always operator. These changes usually result in faster translations and smaller automata. Other improvements reduce non-determinism in the produced automata. In fact, we modified all the steps of the original algorithm and its implementation known as LTL2BA. Experimental results show that our modifications are real improvements. Their implementations within an LTL2BA translation made LTL2BA very competitive with the current version of SPOT, sometimes outperforming it substantially.
Představujeme vylepseni algoritmu, který překlada LTL formule na Buchiho automaty pomoci alternuj... more Představujeme vylepseni algoritmu, který překlada LTL formule na Buchiho automaty pomoci alternujicich automatů. Konkretněji zlepsujeme převod alternujicich Buchiho automatů na generalizovane Buchiho automaty, kde docasně ignorujeme některe přechody vedouci ze stavů alternujiciho automatu, ktere odpovidaji prefixově invariantnim formulim, což může vest k rychlejsimu překladu.
Překlad logiky linearniho casu (Linear Temporal Logic - LTL) na různe typy ɷ-automatů je intenziv... more Překlad logiky linearniho casu (Linear Temporal Logic - LTL) na různe typy ɷ-automatů je intenzivně studovana oblast, ktera ma mnoho aplikaci. Metoda LTL ověřovani modelu (LTL model checking) je rozsiřena a plně automatizovana technika, ktera se použiva k ověřeni, zda daný system splňuje požadovanou specifikaci. Jednim z klicových kroků je překlad logiky LTL na Buchiho automaty. Různe vlastnosti, jako velikost a determinismus použiteho automatu, mohou mit velký vliv na celkový výkon a průběh metody ověřovani modelu. Jine typy automatů, napřiklad deterministicke Rabinovy automaty, se použivaji při ověřovani modelu pravděpodobnostnich systemů. Překlad LTL na ɷ-automaty ma kromě metody ověřovani modelu využiti i v jiných oblastech jako jsou kontrola spravnosti (sanity checking), detekce prazdnosti (vacuity detection), synteza kontrolerů (controller synthesis) a synteza reaktivnich modulů (synthesis of reactive modules). Zlepseni různých překladů LTL na ɷ-automaty se v minulosti věnoval...
Some applications of linear temporal logic (LTL) require to translate formulae of the logic to de... more Some applications of linear temporal logic (LTL) require to translate formulae of the logic to deterministic ω-automata. There are currently two translators producing deterministic automata: ltl2dstar working for the whole LTL and Rabinizer applicable to LTL(F, G) which is the LTL fragment using only modalities F and G. We present a new translation to deterministic Rabin automata via alternating automata and deterministic transition-based generalized Rabin automata. Our translation applies to a fragment that is strictly larger than LTL(F, G). Experimental results show that our algorithm can produce significantly smaller automata compared to Rabinizer and ltl2dstar, especially for more complex LTL formulae.
Recently, there was defined a fragment of LTL (containing fairness properties among other interes... more Recently, there was defined a fragment of LTL (containing fairness properties among other interesting formulae) whose validity over a given infinite word depends only on an arbitrary suffix of the word. Building upon an existing translation from LTL to Büchi automata, we introduce a compositional approach where subformulae of this fragment are translated separately from the rest of an input formula and the produced automata are composed in a way that the subformulae are checked only in relevant accepting strongly connected components of the final automaton. Further, we suggest improvements over some procedures commonly applied to generalized Büchi automata, namely over generalized acceptance simplification and over degeneralization. Finally we show how existing simulation-based reductions can be implemented in a signature-based framework in a way that improves the determinism of the automaton.
Tools and Algorithms for the Construction and Analysis of Systems, 2012
We introduce improvements in the algorithm by Gastin and Oddoux translating LTL formulae into Büc... more We introduce improvements in the algorithm by Gastin and Oddoux translating LTL formulae into Büchi automata via very weak alternating co-Büchi automata and generalized Büchi automata. Several improvements are based on specific properties of any formula where each branch of its syntax tree contains at least one eventually operator and at least one always operator. These changes usually result in faster translations and smaller automata. Other improvements reduce non-determinism in the produced automata. In fact, we modified all the steps of the original algorithm and its implementation known as LTL2BA. Experimental results show that our modifications are real improvements. Their implementations within an LTL2BA translation made LTL2BA very competitive with the current version of SPOT, sometimes outperforming it substantially.
We identify a subtle error in LTL formulas reduction method used as one optimization step in an L... more We identify a subtle error in LTL formulas reduction method used as one optimization step in an LTL to B\"uchi automata translation. The error led to some incorrect answers of the established model checker DiVinE. This paper should help authors of other model checkers to avoid this error.
LTL overovanie modelu je siroko rozsirena a plne automatizovana technika, ktora sa použivana na o... more LTL overovanie modelu je siroko rozsirena a plne automatizovana technika, ktora sa použivana na overenie, ci daný system spĺňa požadovanu specifikaciu. Jedným z kľucových krokov je preklad logiky LTL na Buchiho automaty. Vlastnosti výsledneho automatu, ako su veľkosť a determinizmus, maju veľký vplyv na výkon celej procedury. Zlepseniu tohto prekladu sa už venovalo veľa usilia, napriek tomu maju dnesne prekladace stale ďaleko od dokonalosti. Cieľom dizertacnej prace je zlepsiť obecne preklad logiky LTL na ɷ-automaty s ohľadom na celkový výkon overovania modelu. V praxi sa vacsinou použivaju Buchiho automaty, preto sa v prvom rade chceme venovať zlepseniu tohto prekladu. V tezach prezentujeme niekoľko konkretnych vylepseni prekladu LTL na Buchiho automaty cez veľmi slabe alternujuce automaty. Najvýznamnejsim zlepsenim je takzvane odkladanie. V ďalsej faze nasej prace sa chceme venovať využitiu ostatných typov ɷ-automatov a zhodnotiť ich vplyv na celkový výkon procesu overovania model...
ABSTRACT Some applications of linear temporal logic (LTL) require to translate formulae of the lo... more ABSTRACT Some applications of linear temporal logic (LTL) require to translate formulae of the logic to deterministic omega-automata. There are currently two translators producing deterministic automata: ltl2dstar working for the whole LTL and Rabinizer applicable to LTL(F,G) which is the LTL fragment using only modalities F and G. We present a new translation to deterministic Rabin automata via alternating automata and deterministic transition-based generalized Rabin automata. Our translation applies to a fragment that is strictly larger than LTL(F,G). Experimental results show that our algorithm can produce significantly smaller automata compared to Rabinizer and ltl2dstar, especially for more complex LTL formulae.
Hereby I declare, that this thesis is my original authorial work, which I have worked out by my o... more Hereby I declare, that this thesis is my original authorial work, which I have worked out by my own. All sources, references and literature used or excerpted during elaboration of this work are properly cited and listed in complete reference to the due source.
ABSTRACT We introduce improvements in the algorithm by Gastin and Oddoux translating LTL formulae... more ABSTRACT We introduce improvements in the algorithm by Gastin and Oddoux translating LTL formulae into B\"uchi automata via very weak alternating co-B\"uchi automata and generalized B\"uchi automata. Several improvements are based on specific properties of any formula where each branch of its syntax tree contains at least one eventually operator and at least one always operator. These changes usually result in faster translations and smaller automata. Other improvements reduce non-determinism in the produced automata. In fact, we modified all the steps of the original algorithm and its implementation known as LTL2BA. Experimental results show that our modifications are real improvements. Their implementations within an LTL2BA translation made LTL2BA very competitive with the current version of SPOT, sometimes outperforming it substantially.
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Papers by Tomáš Babiak