---
_id: '5438'
abstract:
- lang: eng
text: "The edit distance between two words w1, w2 is the minimal number of word
operations (letter insertions, deletions, and substitutions) necessary to transform
w1 to w2. The edit distance generalizes to languages L1, L2, where the edit distance
is the minimal number k such that for every word from L1 there exists a word in
L2 with edit distance at most k. We study the edit distance computation problem
between pushdown automata and their subclasses.\r\nThe problem of computing edit
distance to a pushdown automaton is undecidable, and in practice, the interesting
question is to compute the edit distance from a pushdown automaton (the implementation,
a standard model for programs with recursion) to a regular language (the specification).
In this work, we present a complete picture of decidability and complexity for
deciding whether, for a given threshold k, the edit distance from a pushdown automaton
to a finite automaton is at most k. "
alternative_title:
- IST Austria Technical Report
author:
- first_name: Krishnendu
full_name: Chatterjee, Krishnendu
id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87
last_name: Chatterjee
orcid: 0000-0002-4561-241X
- first_name: Thomas A
full_name: Henzinger, Thomas A
id: 40876CD8-F248-11E8-B48F-1D18A9856A87
last_name: Henzinger
orcid: 0000−0002−2985−7724
- first_name: Rasmus
full_name: Ibsen-Jensen, Rasmus
id: 3B699956-F248-11E8-B48F-1D18A9856A87
last_name: Ibsen-Jensen
orcid: 0000-0003-4783-0389
- first_name: Jan
full_name: Otop, Jan
id: 2FC5DA74-F248-11E8-B48F-1D18A9856A87
last_name: Otop
citation:
ama: Chatterjee K, Henzinger TA, Ibsen-Jensen R, Otop J. *Edit Distance for Pushdown
Automata*. IST Austria; 2015. doi:10.15479/AT:IST-2015-334-v1-1
apa: Chatterjee, K., Henzinger, T. A., Ibsen-Jensen, R., & Otop, J. (2015).
*Edit distance for pushdown automata*. IST Austria. https://doi.org/10.15479/AT:IST-2015-334-v1-1
chicago: Chatterjee, Krishnendu, Thomas A Henzinger, Rasmus Ibsen-Jensen, and Jan
Otop. *Edit Distance for Pushdown Automata*. IST Austria, 2015. https://doi.org/10.15479/AT:IST-2015-334-v1-1.
ieee: K. Chatterjee, T. A. Henzinger, R. Ibsen-Jensen, and J. Otop, *Edit distance
for pushdown automata*. IST Austria, 2015.
ista: Chatterjee K, Henzinger TA, Ibsen-Jensen R, Otop J. 2015. Edit distance for
pushdown automata, IST Austria, 15p.
mla: Chatterjee, Krishnendu, et al. *Edit Distance for Pushdown Automata*.
IST Austria, 2015, doi:10.15479/AT:IST-2015-334-v1-1.
short: K. Chatterjee, T.A. Henzinger, R. Ibsen-Jensen, J. Otop, Edit Distance for
Pushdown Automata, IST Austria, 2015.
date_created: 2018-12-12T11:39:20Z
date_published: 2015-05-05T00:00:00Z
date_updated: 2021-01-12T08:02:18Z
day: '05'
ddc:
- '004'
department:
- _id: KrCh
doi: 10.15479/AT:IST-2015-334-v1-1
file:
- access_level: open_access
checksum: 8a5f2d77560e552af87eb1982437a43b
content_type: application/pdf
creator: system
date_created: 2018-12-12T11:53:56Z
date_updated: 2020-07-14T12:46:55Z
file_id: '5518'
file_name: IST-2015-334-v1+1_report.pdf
file_size: 422573
relation: main_file
file_date_updated: 2020-07-14T12:46:55Z
has_accepted_license: '1'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: '15'
publication_identifier:
issn:
- 2664-1690
publication_status: published
publisher: IST Austria
pubrep_id: '334'
related_material:
record:
- id: '465'
relation: later_version
status: public
- id: '1610'
relation: later_version
status: public
status: public
title: Edit distance for pushdown automata
type: technical_report
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2015'
...
---
_id: '5439'
abstract:
- lang: eng
text: 'The target discounted-sum problem is the following: Given a rational discount
factor 0 < λ < 1 and three rational values a, b, and t, does there exist a finite
or an infinite sequence w ε(a, b)∗ or w ε(a, b)w, such that Σ|w| i=0 w(i)λi equals
t? The problem turns out to relate to many fields of mathematics and computer
science, and its decidability question is surprisingly hard to solve. We solve
the finite version of the problem, and show the hardness of the infinite version,
linking it to various areas and open problems in mathematics and computer science:
β-expansions, discounted-sum automata, piecewise affine maps, and generalizations
of the Cantor set. We provide some partial results to the infinite version, among
which are solutions to its restriction to eventually-periodic sequences and to
the cases that λ λ 1/2 or λ = 1/n, for every n ε N. We use our results for solving
some open problems on discounted-sum automata, among which are the exact-value
problem for nondeterministic automata over finite words and the universality and
inclusion problems for functional automata. '
alternative_title:
- IST Austria Technical Report
author:
- first_name: Udi
full_name: Boker, Udi
id: 31E297B6-F248-11E8-B48F-1D18A9856A87
last_name: Boker
- first_name: Thomas A
full_name: Henzinger, Thomas A
id: 40876CD8-F248-11E8-B48F-1D18A9856A87
last_name: Henzinger
orcid: 0000−0002−2985−7724
- first_name: Jan
full_name: Otop, Jan
id: 2FC5DA74-F248-11E8-B48F-1D18A9856A87
last_name: Otop
citation:
ama: Boker U, Henzinger TA, Otop J. *The Target Discounted-Sum Problem*. IST
Austria; 2015. doi:10.15479/AT:IST-2015-335-v1-1
apa: Boker, U., Henzinger, T. A., & Otop, J. (2015). *The target discounted-sum
problem*. IST Austria. https://doi.org/10.15479/AT:IST-2015-335-v1-1
chicago: Boker, Udi, Thomas A Henzinger, and Jan Otop. *The Target Discounted-Sum
Problem*. IST Austria, 2015. https://doi.org/10.15479/AT:IST-2015-335-v1-1.
ieee: U. Boker, T. A. Henzinger, and J. Otop, *The target discounted-sum problem*.
IST Austria, 2015.
ista: Boker U, Henzinger TA, Otop J. 2015. The target discounted-sum problem, IST
Austria, 20p.
mla: Boker, Udi, et al. *The Target Discounted-Sum Problem*. IST Austria, 2015,
doi:10.15479/AT:IST-2015-335-v1-1.
short: U. Boker, T.A. Henzinger, J. Otop, The Target Discounted-Sum Problem, IST
Austria, 2015.
date_created: 2018-12-12T11:39:20Z
date_published: 2015-05-18T00:00:00Z
date_updated: 2021-01-12T08:02:19Z
day: '18'
ddc:
- '004'
- '512'
- '513'
department:
- _id: ToHe
doi: 10.15479/AT:IST-2015-335-v1-1
file:
- access_level: open_access
checksum: 40405907aa012acece1bc26cf0be554d
content_type: application/pdf
creator: system
date_created: 2018-12-12T11:53:55Z
date_updated: 2020-07-14T12:46:55Z
file_id: '5517'
file_name: IST-2015-335-v1+1_report.pdf
file_size: 589619
relation: main_file
file_date_updated: 2020-07-14T12:46:55Z
has_accepted_license: '1'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: '20'
publication_identifier:
issn:
- 2664-1690
publication_status: published
publisher: IST Austria
pubrep_id: '335'
related_material:
record:
- id: '1659'
relation: later_version
status: public
status: public
title: The target discounted-sum problem
type: technical_report
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2015'
...
---
_id: '5432'
abstract:
- lang: eng
text: "Evolution occurs in populations of reproducing individuals. The structure
of the population affects the outcome of the evolutionary process. Evolutionary
graph theory is a powerful approach to study this phenomenon. There are two graphs.
The interaction graph specifies who interacts with whom in the context of evolution.The
replacement graph specifies who competes with whom for reproduction. \r\nThe vertices
of the two graphs are the same, and each vertex corresponds to an individual of
the population. A key quantity is the fixation probability of a new mutant. It
is defined as the probability that a newly introduced mutant (on a single vertex)
generates a lineage of offspring which eventually takes over the entire population
of resident individuals. The basic computational questions are as follows: (i)
the qualitative question asks whether the fixation probability is positive; and
(ii) the quantitative approximation question asks for an approximation of the
fixation probability. \r\nOur main results are:\r\n(1) We show that the qualitative
question is NP-complete and the quantitative approximation question is #P-hard
in the special case when the interaction and the replacement graphs coincide and
even with the restriction that the resident individuals do not reproduce (which
corresponds to an invading population taking over an empty structure).\r\n(2)
We show that in general the qualitative question is PSPACE-complete and the quantitative
approximation question is PSPACE-hard and can be solved in exponential time.\r\n"
alternative_title:
- IST Austria Technical Report
author:
- first_name: Krishnendu
full_name: Chatterjee, Krishnendu
id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87
last_name: Chatterjee
orcid: 0000-0002-4561-241X
- first_name: Rasmus
full_name: Ibsen-Jensen, Rasmus
id: 3B699956-F248-11E8-B48F-1D18A9856A87
last_name: Ibsen-Jensen
orcid: 0000-0003-4783-0389
- first_name: Martin
full_name: Nowak, Martin
last_name: Nowak
citation:
ama: Chatterjee K, Ibsen-Jensen R, Nowak M. *The Complexity of Evolutionary Games
on Graphs*. IST Austria; 2015. doi:10.15479/AT:IST-2015-323-v1-1
apa: Chatterjee, K., Ibsen-Jensen, R., & Nowak, M. (2015). *The complexity
of evolutionary games on graphs*. IST Austria. https://doi.org/10.15479/AT:IST-2015-323-v1-1
chicago: Chatterjee, Krishnendu, Rasmus Ibsen-Jensen, and Martin Nowak. *The Complexity
of Evolutionary Games on Graphs*. IST Austria, 2015. https://doi.org/10.15479/AT:IST-2015-323-v1-1.
ieee: K. Chatterjee, R. Ibsen-Jensen, and M. Nowak, *The complexity of evolutionary
games on graphs*. IST Austria, 2015.
ista: Chatterjee K, Ibsen-Jensen R, Nowak M. 2015. The complexity of evolutionary
games on graphs, IST Austria, 29p.
mla: Chatterjee, Krishnendu, et al. *The Complexity of Evolutionary Games on Graphs*.
IST Austria, 2015, doi:10.15479/AT:IST-2015-323-v1-1.
short: K. Chatterjee, R. Ibsen-Jensen, M. Nowak, The Complexity of Evolutionary
Games on Graphs, IST Austria, 2015.
date_created: 2018-12-12T11:39:18Z
date_published: 2015-02-19T00:00:00Z
date_updated: 2021-01-12T08:02:20Z
day: '19'
ddc:
- '005'
- '576'
department:
- _id: KrCh
doi: 10.15479/AT:IST-2015-323-v1-1
file:
- access_level: open_access
checksum: 546c1b291d545e7b24aaaf4199dac671
content_type: application/pdf
creator: system
date_created: 2018-12-12T11:53:57Z
date_updated: 2020-07-14T12:46:53Z
file_id: '5519'
file_name: IST-2015-323-v1+1_main.pdf
file_size: 576347
relation: main_file
file_date_updated: 2020-07-14T12:46:53Z
has_accepted_license: '1'
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
page: '29'
publication_identifier:
issn:
- 2664-1690
publication_status: published
publisher: IST Austria
pubrep_id: '323'
related_material:
record:
- id: '5421'
relation: earlier_version
status: public
- id: '5440'
relation: later_version
status: public
status: public
title: The complexity of evolutionary games on graphs
type: technical_report
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2015'
...
---
_id: '5440'
abstract:
- lang: eng
text: 'Evolution occurs in populations of reproducing individuals. The structure
of the population affects the outcome of the evolutionary process. Evolutionary
graph theory is a powerful approach to study this phenomenon. There are two graphs.
The interaction graph specifies who interacts with whom for payoff in the context
of evolution. The replacement graph specifies who competes with whom for reproduction.
The vertices of the two graphs are the same, and each vertex corresponds to an
individual of the population. The fitness (or the reproductive rate) is a non-negative
number, and depends on the payoff. A key quantity is the fixation probability
of a new mutant. It is defined as the probability that a newly introduced mutant
(on a single vertex) generates a lineage of offspring which eventually takes over
the entire population of resident individuals. The basic computational questions
are as follows: (i) the qualitative question asks whether the fixation probability
is positive; and (ii) the quantitative approximation question asks for an approximation
of the fixation probability. Our main results are as follows: First, we consider
a special case of the general problem, where the residents do not reproduce. We
show that the qualitative question is NP-complete, and the quantitative approximation
question is #P-complete, and the hardness results hold even in the special case
where the interaction and the replacement graphs coincide. Second, we show that
in general both the qualitative and the quantitative approximation questions are
PSPACE-complete. The PSPACE-hardness result for quantitative approximation holds
even when the fitness is always positive.'
alternative_title:
- IST Austria Technical Report
author:
- first_name: Krishnendu
full_name: Chatterjee, Krishnendu
id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87
last_name: Chatterjee
orcid: 0000-0002-4561-241X
- first_name: Rasmus
full_name: Ibsen-Jensen, Rasmus
id: 3B699956-F248-11E8-B48F-1D18A9856A87
last_name: Ibsen-Jensen
orcid: 0000-0003-4783-0389
- first_name: Martin
full_name: Nowak, Martin
last_name: Nowak
citation:
ama: Chatterjee K, Ibsen-Jensen R, Nowak M. *The Complexity of Evolutionary Games
on Graphs*. IST Austria; 2015. doi:10.15479/AT:IST-2015-323-v2-2
apa: Chatterjee, K., Ibsen-Jensen, R., & Nowak, M. (2015). *The complexity
of evolutionary games on graphs*. IST Austria. https://doi.org/10.15479/AT:IST-2015-323-v2-2
chicago: Chatterjee, Krishnendu, Rasmus Ibsen-Jensen, and Martin Nowak. *The Complexity
of Evolutionary Games on Graphs*. IST Austria, 2015. https://doi.org/10.15479/AT:IST-2015-323-v2-2.
ieee: K. Chatterjee, R. Ibsen-Jensen, and M. Nowak, *The complexity of evolutionary
games on graphs*. IST Austria, 2015.
ista: Chatterjee K, Ibsen-Jensen R, Nowak M. 2015. The complexity of evolutionary
games on graphs, IST Austria, 18p.
mla: Chatterjee, Krishnendu, et al. *The Complexity of Evolutionary Games on Graphs*.
IST Austria, 2015, doi:10.15479/AT:IST-2015-323-v2-2.
short: K. Chatterjee, R. Ibsen-Jensen, M. Nowak, The Complexity of Evolutionary
Games on Graphs, IST Austria, 2015.
date_created: 2018-12-12T11:39:21Z
date_published: 2015-06-16T00:00:00Z
date_updated: 2021-01-12T08:02:20Z
day: '16'
ddc:
- '005'
- '576'
department:
- _id: KrCh
doi: 10.15479/AT:IST-2015-323-v2-2
file:
- access_level: open_access
checksum: 66aace7d367032af97c15e35c9be9636
content_type: application/pdf
creator: system
date_created: 2018-12-12T11:53:23Z
date_updated: 2020-07-14T12:46:56Z
file_id: '5484'
file_name: IST-2015-323-v2+2_main.pdf
file_size: 466161
relation: main_file
file_date_updated: 2020-07-14T12:46:56Z
has_accepted_license: '1'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
page: '18'
publication_identifier:
issn:
- 2664-1690
publication_status: published
publisher: IST Austria
pubrep_id: '338'
related_material:
record:
- id: '5421'
relation: earlier_version
status: public
- id: '5432'
relation: earlier_version
status: public
status: public
title: The complexity of evolutionary games on graphs
type: technical_report
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2015'
...
---
_id: '5443'
abstract:
- lang: eng
text: POMDPs are standard models for probabilistic planning problems, where an agent
interacts with an uncertain environment. We study the problem of almost-sure reachability,
where given a set of target states, the question is to decide whether there is
a policy to ensure that the target set is reached with probability 1 (almost-surely).
While in general the problem is EXPTIME-complete, in many practical cases policies
with a small amount of memory suffice. Moreover, the existing solution to the
problem is explicit, which first requires to construct explicitly an exponential
reduction to a belief-support MDP. In this work, we first study the existence
of observation-stationary strategies, which is NP-complete, and then small-memory
strategies. We present a symbolic algorithm by an efficient encoding to SAT and
using a SAT solver for the problem. We report experimental results demonstrating
the scalability of our symbolic (SAT-based) approach.
alternative_title:
- IST Austria Technical Report
author:
- first_name: Krishnendu
full_name: Chatterjee, Krishnendu
id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87
last_name: Chatterjee
orcid: 0000-0002-4561-241X
- first_name: Martin
full_name: Chmelik, Martin
id: 3624234E-F248-11E8-B48F-1D18A9856A87
last_name: Chmelik
- first_name: Jessica
full_name: Davies, Jessica
id: 378E0060-F248-11E8-B48F-1D18A9856A87
last_name: Davies
citation:
ama: Chatterjee K, Chmelik M, Davies J. *A Symbolic SAT-Based Algorithm for Almost-Sure
Reachability with Small Strategies in POMDPs*. IST Austria; 2015. doi:10.15479/AT:IST-2015-325-v2-1
apa: Chatterjee, K., Chmelik, M., & Davies, J. (2015). *A symbolic SAT-based
algorithm for almost-sure reachability with small strategies in POMDPs*. IST
Austria. https://doi.org/10.15479/AT:IST-2015-325-v2-1
chicago: Chatterjee, Krishnendu, Martin Chmelik, and Jessica Davies. *A Symbolic
SAT-Based Algorithm for Almost-Sure Reachability with Small Strategies in POMDPs*.
IST Austria, 2015. https://doi.org/10.15479/AT:IST-2015-325-v2-1.
ieee: K. Chatterjee, M. Chmelik, and J. Davies, *A symbolic SAT-based algorithm
for almost-sure reachability with small strategies in POMDPs*. IST Austria,
2015.
ista: Chatterjee K, Chmelik M, Davies J. 2015. A symbolic SAT-based algorithm for
almost-sure reachability with small strategies in POMDPs, IST Austria, 23p.
mla: Chatterjee, Krishnendu, et al. *A Symbolic SAT-Based Algorithm for Almost-Sure
Reachability with Small Strategies in POMDPs*. IST Austria, 2015, doi:10.15479/AT:IST-2015-325-v2-1.
short: K. Chatterjee, M. Chmelik, J. Davies, A Symbolic SAT-Based Algorithm for
Almost-Sure Reachability with Small Strategies in POMDPs, IST Austria, 2015.
date_created: 2018-12-12T11:39:22Z
date_published: 2015-11-06T00:00:00Z
date_updated: 2021-01-12T08:02:23Z
day: '06'
ddc:
- '000'
department:
- _id: KrCh
doi: 10.15479/AT:IST-2015-325-v2-1
file:
- access_level: open_access
checksum: f0fa31ad8161ed655137e94012123ef9
content_type: application/pdf
creator: system
date_created: 2018-12-12T11:53:05Z
date_updated: 2020-07-14T12:46:57Z
file_id: '5466'
file_name: IST-2015-325-v2+1_main.pdf
file_size: 412379
relation: main_file
file_date_updated: 2020-07-14T12:46:57Z
has_accepted_license: '1'
language:
- iso: eng
month: '11'
oa: 1
oa_version: Published Version
page: '23'
publication_identifier:
issn:
- 2664-1690
publication_status: published
publisher: IST Austria
pubrep_id: '362'
related_material:
record:
- id: '1166'
relation: later_version
status: public
status: public
title: A symbolic SAT-based algorithm for almost-sure reachability with small strategies
in POMDPs
type: technical_report
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2015'
...