@string{brics =	"{BRICS}"}
@string{daimi =	"Department of Computer Science, University of Aarhus"}
@string{iesd  =	"Department of Computer Science, Institute
of Electronic Systems, Aalborg University"}
@string{rs    =	"Research Series"}
@string{ns    =	"Notes Series"}
@string{ls    =	"Lecture Series"}
@string{ds    =	"Dissertation Series"}

@techreport{BRICS-RS-03-53,
author = 	 "Doh, Kyung-Goo and Mosses, Peter D.",
title = 	 "Composing Programming Languages by Combining
Action-Semantics Modules",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-53",
month = 	 dec,
note = 	 "39~pp. Appears in {\em Science of Computer
Programming}, 47(1):2--36, 2003",
composing a programming language by combining
action-semantics modules. Each module is
defined separately, and then a
programming-language module is defined by
combining existing modules. This method enables
the language designer to gradually develop a
language by defining, selecting and combining
suitable modules. The resulting modular
structure is substantially different from that
previously employed in action-semantic
descriptions.\bibpar
It also discusses how to resolve the conflicts
that may arise when combining modules, and
indicates some advantages that action semantics
has over other approaches in this respect.",
}

@techreport{BRICS-RS-03-52,
author = 	 "Mosses, Peter D.",
title = 	 "Pragmatics of Modular {SOS}",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-52",
month = 	 dec,
note = 	 "22~pp. Invited paper, published in " #
lncs2422 # ", pages 21--40",
abstract = 	 "Modular SOS is a recently-developed variant of
Plotkin's Structural Operational Semantics
(SOS) framework. It has several pragmatic
most significant being that rules specifying
the semantics of individual language constructs
can be given {\em definitively}, once and for
all.\bibpar
Modular SOS is being used for teaching
level. For this purpose, the meta-notation for
modular SOS rules has been made more
user-friendly, and derivation of computations
according to the rules is simulated using
Prolog.\bibpar
After giving an overview of the foundations of
Modular SOS, this paper gives some illustrative
examples of the use of the framework, and
discusses various pragmatic aspects.",
}

@techreport{BRICS-RS-03-51,
author = 	 "Kohlenbach, Ulrich and Lambov, Branimir",
title = 	 "Bounds on Iterations of Asymptotically
Quasi-Nonexpansive Mappings",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-51",
month = 	 dec,
note = 	 "24~pp",
abstract = 	 "This paper establishes explicit quantitative
bounds on the computation of approximate fixed
points of asymptotically (quasi-) nonexpansive
mappings $f$ by means of iterative processes.
Here $f:C\to C$ is a selfmapping of a convex
subset $C\subseteq X$ of a uniformly convex
normed space $X$. We consider general
Krasnoselski-Mann iterations with and without
error terms. As a consequence of our
quantitative analysis we also get new
qualitative results which show that the
assumption on the existence of fixed points of
$f$ can be replaced by the existence of
approximate fixed points only. We explain how
the existence of effective uniform bounds in
this context can be inferred already a-priorily
by a logical metatheorem recently proved by the
first author. Our bounds were in fact found
with the help of the general logical machinery
behind the proof of this metatheorem. The
proofs we present here are, however, completely
selfcontained and do not require any tools from
logic.",
}

@techreport{BRICS-RS-03-50,
author = 	 "Lambov, Branimir",
title = 	 "A Two-Layer Approach to the Computability and
Complexity of Real Numbers",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-50",
month = 	 dec,
note = 	 "16~pp",
abstract = 	 "We present a new approach to computability of
real numbers in which real functions have
type-1 representations, which also includes the
ability to reason about the complexity of real
numbers and functions. We discuss how this
allows efficient implementations of exact real
numbers and also present a new real number
system that is based on it.",
}

@techreport{BRICS-RS-03-49,
author = 	 "Mikucionis, Marius and Larsen, Kim G. and
Nielsen, Brian",
title = 	 "Online On-the-Fly Testing of Real-time
Systems",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-49",
month = 	 dec,
note = 	 "14~pp",
keywords = 	 "testing, real-time systems, embedded systems,
timed trace inclusion, on-the-fly, online,
conformance, UppAal, conformance testing,
automated test derivation, test generation and
execution, model-based testing, real-time
infinite state space, state-set estimation",
abstract = 	 "In this paper we present a framework, an
algorithm and a new tool for online testing of
real-time systems based on symbolic techniques
used in UPPAAL model checker. We extend UPPAAL
timed automata network model to a test
specification which is used to generate test
primitives and to check the correctness of
system responses including the timing aspects.
We use timed trace inclusion as a conformance
relation between system and specification to
draw a test verdict. The test generation and
execution algorithm is implemented as an
extension to UPPAAL and experiments carried out
to examine the correctness and performance of
the tool. The experiment results are
promising",
}

@techreport{BRICS-RS-03-48,
author = 	 "Larsen, Kim G. and Larsen, Ulrik and Nielsen,
Brian and Skou, Arne and Wasowski, Andrzej",
title = 	 "Danfoss {EKC} Trial Project Deliverables",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-48",
month = 	 dec,
note = 	 "53~pp",
abstract = 	 "This report documents the results of the
Danfoss EKC trial project on model based
development using IAR visualState. We present a
formal state-model of an refrigeration
controller based on a specification given by
Danfoss. We report results on modeling,
verification, simulation, and code-generation.
It is found that the IAR visualState is a
promising tool for this application domain, but
that improvements must be done to
code-generation and automatic test
generation.",
}

@techreport{BRICS-RS-03-47,
author = 	 "H{\"u}ttel, Hans and Srba, Ji{\v{r}}{\'\i}",
title = 	 "Recursive Ping-Pong Protocols",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-47",
month = 	 dec,
note = 	 "21~pp. To appear in the proceedings of 2004
IFIP WG 1.7, ACM SIGPLAN and GI FoMSESS
Workshop on Issues in the Theory of Security
(WITS'04)",
abstract = 	 "This paper introduces a process calculus with
recursion which allows us to express an
unbounded number of runs of the ping-pong
protocols introduced by Dolev and Yao. We study
the decidability issues associated with two
common approaches to checking security
properties, namely reachability analysis and
bisimulation checking. Our main result is that
our channel-free and memory-less calculus is
Turing powerful, assuming that at least three
principals are involved. We also investigate
the expressive power of the calculus in the
case of two participants. Here, our main
results are that reachability and, under
certain conditions, also strong bisimilarity
become decidable. ",
}

@techreport{BRICS-RS-03-46,
author = 	 "Gerhardy, Philipp",
title = 	 "The Role of Quantifier Alternations in Cut
Elimination",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-46",
month = 	 dec,
note = 	 "10~pp. Extends paper appearing in " # lncs2803
# ", pages 212-225",
abstract = 	 "Extending previous results from the author's
master's thesis, subsequently published in the
proceedings of CSL 2003, on the complexity of
cut elimination for the sequent calculus {\bf
LK}, we discuss the role of quantifier
alternations and develope a measure to describe
the complexity of cut elimination in terms of
quantifier alternations in cut formulas and
contractions on such formulas",
}

@techreport{BRICS-RS-03-45,
author = 	 "Miltersen, Peter Bro and Radhakrishnan,
Jaikumar and Wegener, Ingo",
title = 	 "On converting {CNF} to {DNF}",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-45",
month = 	 dec,
note = 	 "11~pp. A preliminary version appeared in " #
lncs2747 # ", pages 612--621",
abstract = 	 "We study how big the blow-up in size can be
when one switches between the CNF and DNF
representations of boolean functions. For a
function $f:\{0,1\}^n \rightarrow\{0,1\}$,
$\mbox{\sf cnfsize}(f)$ denotes the minimum
number of clauses in a CNF for $f$; similarly,
$\mbox{\sf dnfsize}(f)$ denotes the minimum
number of terms in a DNF for $f$. For $0\leq m \leq 2^{n-1}$, let $\mbox{\sf dnfsize}(m,n)$ be
the maximum $\mbox{\sf dnfsize}(f)$ for a
function $f:\{0,1\}^n \rightarrow\{0,1\}$ with
$\mbox{\sf cnfsize}(f) \leq m$. We show that
there are constants $c_1,c_2 \geq 1$ and
$\epsilon> 0$, such that for all large $n$ and
all $m \in[ \frac{1}{\epsilon}n,2^{\epsilon {n}}]$, we have $2^{n - c_1\frac{n}{\log (m/n)}}~ \leq~\mbox{\sf dnfsize}(m,n) ~\leq~ 2^{n-c_2 \frac{n}{\log(m/n)}}.$ In particular,
when $m$ is the polynomial $n^c$, we get $\mbox {\sf dnfsize}(n^c,n) = 2^{n -\theta(c^{-1}\frac {n}{\log n})}$.",
}

@techreport{BRICS-RS-03-44,
author = 	 "G{\'a}l, Anna and Miltersen, Peter Bro",
title = 	 "The Cell Probe Complexity of Succinct Data
Structures",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-44",
month = 	 dec,
note = 	 "17~pp. Appears in " # lncs2751 # ", pages
442--453. An early version of this paper
appeared in " # lncs2719 # ", pages 332--344",
abstract = 	 "In the cell probe model with word size 1 (the
bit probe model), a static data structure
problem is given by a map $f: \{0,1\}^n \times \{0,1\}^m \rightarrow\{0,1\}$, where
$\{0,1\}^n$ is a set of possible data to be
stored, $\{0,1\}^m$ is a set of possible
queries (for natural problems, we have $m \ll n$) and $f(x,y)$ is the answer to question $y$
about data $x$.\bibpar
A solution is given by a representation $\phi: \{0,1\}^n \rightarrow\{0,1\}^s$ and a query
algorithm $q$ so that $q(\phi(x), y) = f(x,y)$.
The time $t$ of the query algorithm is the
number of bits it reads in $\phi(x)$.\bibpar
In this paper, we consider the case of {\em
succinct} representations where $s = n + r$ for
some {\em redundancy} $r \ll n$. For a boolean
version of the problem of polynomial evaluation
with preprocessing of coefficients, we show a
lower bound on the redundancy-query time
tradeoff of the form $(r+1) t \geq\Omega (n/\log n).$ In particular, for very small
redundancies $r$, we get an almost optimal
lower bound stating that the query algorithm
has to inspect almost the entire data structure
(up to a logarithmic factor). We show similar
lower bounds for problems satisfying a certain
combinatorial property of a coding theoretic
flavor. Previously, no $\omega(m)$ lower bounds
were known on $t$ in the general model for
explicit functions, even for very small
redundancies.\bibpar
By restricting our attention to {\em
systematic} or {\em index} structures $\phi$
satisfying $\phi(x) = x \cdot\phi^*(x)$ for
some map $\phi^*$ (where $\cdot$ denotes
concatenation) we show similar lower bounds on
the redundancy-query time tradeoff for the
natural data structuring problems of Prefix Sum
and Substring Search.",
}
@techreport{BRICS-RS-03-43,
author = 	 "Nygaard, Mikkel and Winskel, Glynn",
title = 	 "Domain Theory for Concurrency",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-43",
month = 	 dec,
note = 	 "45~pp. To appear in a {\em Theoretical
Computer Science\/} special issue on Domain
Theory",
abstract = 	 "A simple domain theory for concurrency is
presented. Based on a categorical model of
linear logic and associated comonads, it
highlights the role of linearity in concurrent
computation. Two choices of comonad yield two
expressive metalanguages for higher-order
processes, both arising from canonical
constructions in the model. Their denotational
semantics are fully abstract with respect to
contextual equivalence. One language derives
from an exponential of linear logic; it
supports a straightforward operational
semantics with simple proofs of soundness and
model of affine-linear logic, and a process
language with a tensor operation to be
understood as a parallel composition of
independent processes. The domain theory can be
generalised to presheaf models, providing a
more refined treatment of nondeterministic
branching. The article concludes with a
discussion of a broader programme of research,
towards a fully fledged domain theory for
concurrency.",
}

@techreport{BRICS-RS-03-42,
author = 	 "Nygaard, Mikkel and Winskel, Glynn",
title = 	 "Full Abstraction for {HOPLA}",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-42",
month = 	 dec,
note = 	 "25~pp. Appears in " # lncs2761 # ", pages
383--398",
abstract = 	 "A fully abstract denotational semantics for
the higher-order process language HOPLA is
presented. It characterises contextual and
logical equivalence, the latter linking up with
simulation. The semantics is a clean,
domain-theoretic description of processes as
downwards-closed sets of computation paths: the
operations of HOPLA arise as syntactic
encodings of canonical constructions on such
sets; full abstraction is a direct consequence
of expressiveness with respect to computation
paths; and simple proofs of soundness and
denotational and operational semantics.",
}

@techreport{BRICS-RS-03-41,
author = 	 "Biernacka, Malgorzata and Biernacki, Dariusz
and Danvy, Olivier",
title = 	 "An Operational Foundation for Delimited
Continuations",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-41",
month = 	 dec,
note = 	 "21~pp",
abstract = 	 "We derive an abstract machine that corresponds
to a definitional interpreter for the control
operators shift and reset. Based on this
abstract machine, we construct a syntactic
theory of delimited continuations.\bibpar
Both the derivation and the construction scale
to the family of control operators shift$_n$
and reset$_n$. The definitional interpreter for
shift$_n$ and reset$_n$ has $n+1$ layers of
continuations, the corresponding abstract
machine has $n+1$ layers of control stacks, and
the corresponding syntactic theory has $n+1$
layers of evaluation contexts.",
}

@techreport{BRICS-RS-03-40,
author = 	 "Filinski, Andrzej and Rohde, Henning
Korsholm",
title = 	 "A Denotational Account of Untyped
Normalization by Evaluation",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-40",
month = 	 dec,
note = 	 "29~pp",
abstract = 	 "We show that the standard
normalization-by-evaluation construction for
the simply-typed $\lambda_{\beta\eta}$-calculus
has a natural counterpart for the untyped
$\lambda_\beta$-calculus, with the central
type-indexed logical relation replaced by a
recursively defined'' \emph{invariant
relation}, in the style of Pitts. In fact, the
construction can be seen as generalizing a
of evaluation.\bibpar
In the untyped setting, not all terms have
normal forms, so the normalization function is
necessarily partial. We establish its
correctness in the senses of \emph{soundness}
(the output term, if any, is $\beta$-equivalent
to the input term); \emph{standardization}
($\beta$-equivalent terms are mapped to the
same result); and \emph{completeness} (the
function is defined for all terms that do have
normal forms). We also show how the semantic
construction enables a simple yet formal
correctness proof for the normalization
algorithm, expressed as a functional program in
an ML-like call-by-value language.",
}

@techreport{BRICS-RS-03-39,
author = 	 "Abendroth, J{\"o}rg",
title = 	 "Applying $\pi$-Calculus to Practice: An
Example of a Unified Security Mechanism",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-39",
month = 	 nov,
note = 	 "35~pp",
abstract = 	 "The Pi-calculus has been developed to reason
notions of equivalence are defined in terms of
process interactions, as well as the context of
processes. There are various extensions of the
Pi-calculus, such as the SPI calculus, which
has primitives to facilitate security protocol
design.\bibpar
Another area of computer security is access
control research, which includes problems of
access control models, policies and access
control mechanism. The design of a unified
framework for access control requires that all
policies are supported and different access
control models are instantiated
correctly.\bibpar
In this paper we will utilise the Pi calculus
to reason about access control policies and
mechanism. An equivalence of different policy
implementations, as well as access control
mechanism will be shown. Finally some
experiences regarding the use of Pi-calculus
are presented.",
}

@techreport{BRICS-RS-03-38,
author = 	 "B{\"o}ttger, Henning and M{\o}ller, Anders and
Schwartzbach, Michael I.",
title = 	 "Contracts for Cooperation between Web Service
Programmers and {HTML} Designers",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-38",
month = 	 nov,
note = 	 "23~pp",
abstract = 	 "Interactive Web services consist of a mixture
of HTML fragments and program code. The
fragments, which are maintained by designers,
are combined to form HTML pages that are shown
to the clients. The code, which is maintained
by programmers, is executed on the server to
handle the business logic. Current Web service
frameworks provide little help in separating
these constituents, which complicates
cooperation between programmers and HTML
designers.\bibpar
We propose a system based on XML templates and
formalized contracts allowing a flexible
separation of concerns. The contracts act as
interfaces between the programmers and the HTML
designers and permit tool support for
statically checking that both parties fulfill
their obligations. This ensures that (1)
programmers and HTML designers work more
independently focusing on their own expertises,
(2) the Web service implementation is better
structured and thus easier to develop and
maintain, (3) it is guaranteed that only valid
HTML is sent to the clients even though it is
constructed dynamically, (4) the programmer
uses the XML templates consistently, and (5)
the form input fields being sent to the client
always match the code receiving those values.
Additionally, we describe tools that aid in the
construction and management of contracts and
XML templates",
}

@techreport{BRICS-RS-03-37,
author = 	 "Cr{\'e}peau, Claude and Dumais, Paul and
Mayers, Dominic and Salvail, Louis",
title = 	 "Computational Collapse of Quantum State with
Application to Oblivious Transfer",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-37",
month = 	 nov,
note = 	 "30~pp",
abstract = 	 "Quantum 2-party cryptography differs from its
classical counterpart in at least one important
commitment scheme there exists a secure $1-2$
{\em quantum} oblivious transfer. This
reduction proposed by Cr{\'e}peau and Kilian
was proved secure against any receiver by Yao,
in the case where perfect commitments are used.
However, quantum commitments would normally be
based on computational assumptions. A natural
question therefore arises: What happens to the
security of the above reduction when
computationally secure commitments are used
In this paper, we address the security of $1-2$
QOT when computationally binding string
commitments are available. In particular, we
analyse the security of a primitive called {\em
Quantum Measurement Commitment} when it is
constructed from unconditionally concealing but
computationally binding commitments. As
measuring a quantum state induces an
irreversible collapse, we describe a QMC as an
instance of computational collapse of a
quantum state''. In a QMC a state appears to be
collapsed to a polynomial time observer who
cannot extract full information about the state
without breaking a computational
assumption.\bibpar
We reduce the security of QMC to a {\em weak}
binding criteria for the string commitment. We
also show that {\em secure} QMCs implies QOT
using a straightforward variant of the
reduction above",
}

@techreport{BRICS-RS-03-36,
author =	 "Damg{\aa}rd, Ivan B. and Fehr, Serge and Morozov,
Kirill and Salvail, Louis",
title =	 "Unfair Noisy Channels and Oblivious Transfer",
institution =	 brics,
year =	 2003,
type =	 rs,
number =	 "RS-03-36",
month =	 nov,
note =	 "26~pp. Appears in " # lncs2951 # ", pages 355--373",
abstract =	 "In a paper from EuroCrypt'99, Damg{\aa}rd, Kilian
and Salvail show various positive and negative
results on constructing Bit Commitment (BC) and
Oblivious Transfer (OT) from Unfair Noisy Channels
(UNC), i.e., binary symmetric channels where the
error rate is only known to be in a certain interval
$[\gamma ..\delta]$ and can be chosen
adversarily. They also introduce a related primitive
called $PassiveUNC$. We prove in this paper that any
OT protocol that can be constructed based on a
$PassiveUNC$ and is secure against a passive
adversary can be transformed using a generic
compiler'' into an OT protocol based on a $UNC$
which is secure against an active adversary. Apart
from making positive results easier to prove in
general, this also allows correcting a problem in
the EuroCrypt'99 paper: There, a positive result was
claimed on constructing from UNC an OT that is
secure against active cheating. We point out that
the proof sketch given for this was incomplete, and
we show that a correct proof of a much stronger
result follows from our general compilation result
and a new technique for transforming between weaker
versions of OT with different parameters.",
OPTannote =	 ""
}
@techreport{BRICS-RS-03-35,
author = 	 "Ager, Mads Sig and Danvy, Olivier and
Midtgaard, Jan",
title = 	 "A Functional Correspondence between Monadic
Evaluators and Abstract Machines for Languages
with Computational Effects",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-35",
month = 	 nov,
note = 	 "31~pp",
keywords = 	 "Lambda-calculus, interpreters, abstract
machines, closure conversion, transformation
into continuation-passing style (CPS),
tail recursion, stack inspection",
abstract = 	 "We extend our correspondence between
evaluators and abstract machines from the pure
setting of the lambda-calculus to the impure
setting of the computational lambda-calculus.
Specifically, we show how to derive new
abstract machines from monadic evaluators for
the computational lambda-calculus. Starting
inline the components of the monad in the
evaluator and we derive the corresponding
abstract machine by closure-converting,
CPS-transforming, and defunctionalizing this
inlined interpreter. We illustrate the
construction first with the identity monad,
obtaining yet again the CEK machine, and then
combination of both.\bibpar
In addition, we characterize the tail-recursive
stack inspection presented by Clements and
Felleisen at ESOP 2003 as a canonical state
exception monad, we construct an abstract
machine for a language with exceptions and
properly tail-recursive stack inspection. The
one more properly dedicated to stack inspection
evaluators",
}

@techreport{BRICS-RS-03-34,
author = 	 "Aceto, Luca and Fokkink, Willem Jan and
Ing{\'o}lfsd{\'o}ttir, Anna and Luttik, Bas",
title = 	 "{CCS} with {H}ennessy's Merge has no Finite
Equational Axiomatization",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-34",
month = 	 nov,
note = 	 "37~pp",
abstract = 	 "This paper confirms a conjecture of Bergstra
and Klop's from 1984 by establishing that the
process algebra obtained by adding an auxiliary
operator proposed by Hennessy in 1981 to the
recursion free fragment of Milner's Calculus of
Communicationg Systems is not finitely based
modulo bisimulation equivalence. Thus
Hennessy's merge cannot replace the left merge
and communication merge operators proposed by
Bergstra and Klop, at least if a finite
axiomatization of parallel composition is
desired",
}

@techreport{BRICS-RS-03-33,
author = 	 "Danvy, Olivier",
title = 	 "A Rational Deconstruction of {L}andin's {SECD}
Machine",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-33",
month = 	 oct,
note = 	 "32~pp. This report supersedes the earlier
BRICS report RS-02-53",
abstract = 	 "Landin's SECD machine was the first abstract
machine for the $\lambda$-calculus viewed as a
programming language. Both theoretically as a
model of computation and practically as an
idealized implementation, it has set the tone
for the subsequent development of abstract
machines for functional programming languages.
However, and even though variants of the SECD
machine have been presented, derived, and
invented, the precise rationale for its
architecture and modus operandi has remained
SECD machine into a $\lambda$-interpreter,
i.e., an evaluation function, and we
reconstruct $\lambda$-interpreters into a
variety of SECD-like machines. The
deconstruction and reconstructions are
transformational: they are based on equational
reasoning and on a combination of simple
program transformations---mainly closure
conversion, transformation into
continuation-passing style, and
defunctionalization.\bibpar

The evaluation function underlying the SECD
machine provides a precise rationale for its
architecture: it is an environment-based
eval-apply evaluator with a callee-save
strategy for the environment, a data stack of
intermediate results, and a control delimiter.
Each of the components of the SECD machine
(stack, environment, control, and dump) is
therefore rationalized and so are its
transitions.\bibpar

The deconstruction and reconstruction method
also applies to other abstract machines and
other evaluation functions. It makes it
possible to systematically extract the
denotational content of an abstract machine in
the form of a compositional evaluation
function, and the (small-step) operational
content of an evaluation function in the form
of an abstract machine.",
}

@techreport{BRICS-RS-03-32,
author = 	 "Gerhardy, Philipp and Kohlenbach, Ulrich",
title = 	 "Extracting {H}erbrand Disjunctions by
Functional Interpretation",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-32",
month = 	 oct,
note = 	 "17~pp",
abstract = 	 "Carrying out a suggestion by Kreisel, we adapt
G{\"o}del's functional interpretation to
ordinary first-order predicate logic(PL) and
thus devise an algorithm to extract Herbrand
terms from PL-proofs. The extraction is carried
out in an extension of PL to higher types. The
algorithm consists of two main steps: first we
extract a functional realizer, next we compute
the $\beta$-normal-form of the realizer from
which the Herbrand terms can be read off. Even
though the extraction is carried out in the
extended language, the terms are ordinary
PL-terms. In contrast to approaches to
Herbrand's theorem based on cut elimination or
$\varepsilon$-elimination this extraction
technique is, except for the normalization
step, of low polynomial complexity, fully
modular and furthermore allows an analysis of
the structure of the Herbrand terms, in the
spirit of Kreisel, already prior to the
normalization step. It is expected that the
implementation of functional interpretation in
Schwichtenberg's MINLOG system can be adapted
to yield an efficient Herbrand-term extraction
tool.",
}

@techreport{BRICS-RS-03-31,
author = 	 "Lack, Stephen and Soboci{\'n}ski, Pawe{\l}",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-31",
month = 	 oct,
note = 	 "25~pp",
abstract = 	 "We introduce adhesive categories, which are
categories with structure ensuring that
pushouts along monomorphisms are well-behaved.
Many types of graphical structures used in
computer science are shown to be examples of
rewriting generalises well to rewriting on
}

@techreport{BRICS-RS-03-30,
author = 	 "Byskov, Jesper Makholm and Madsen, Bolette
Ammitzb{\o}ll and Skjernaa, Bjarke",
title = 	 "New Algorithms for Exact Satisfiability",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-30",
month = 	 oct,
note = 	 "31~pp",
abstract = 	 "The Exact Satisfiability problem is to
determine if a CNF-formula has a truth
assignment satisfying exactly one literal in
each clause; Exact 3-Satisfiability is the
version in which each clause contains at most
three literals. In this paper, we present
algorithms for Exact Satisfiability and Exact
3-Satisfiability running in time
$O(2^{0.2325n})$ and $O(2^{0.1379n})$,
respectively. The previously best algorithms
have running times $O(2^{0.2441n})$ for Exact
Satisfiability (Monien, Speckenmeyer and
Vornberger (1981)) and $O(2^{0.1626n})$ for
Exact 3-Satisfiability (Kulikov and
independently Porschen, Randerath and
Speckenmeyer (2002)). We extend the case
analyses of these papers and observe, that a
formula not satisfying any of our cases has a
small number of variables, for which we can try
all possible truth assignments and for each
such assignment solve the remaining part of the
formula in polynomial time.",
}

@techreport{BRICS-RS-03-29,
author = 	 "Christensen, Aske Simon and Kirkegaard,
Christian and M{\o}ller, Anders",
title = 	 "A Runtime System for {XML} Transformations in
Java",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-29",
month = 	 oct,
note = 	 "15~pp",
abstract = 	 "We show that it is possible to extend a
general-purpose programming language with a
convenient high-level data-type for
manipulating XML documents while permitting (1)
precise static analysis for guaranteeing
validity of the constructed XML documents
relative to the given DTD schemas, and (2) a
runtime system where the operations can be
performed efficiently. The system, named {\sc
Xact}, is based on a notion of immutable XML
templates and uses XPath for deconstructing
documents. A companion paper presents the
program analysis; this paper focuses on the
efficient runtime representation.",
}

@techreport{BRICS-RS-03-28,
author = 	 "{\'E}sik, Zolt{\'a}n and Larsen, Kim G.",
title = 	 "Regular Languages Definable by Lindstr{\"o}m
Quantifiers",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-28",
month = 	 aug,
note = 	 "82~pp. This report supersedes the earlier
BRICS report RS-02-20",
abstract = 	 "In our main result, we establish a formal
connection between Lindstr{\"o}m quantifiers
with respect to regular languages and the
double semidirect product of finite monoids
with a distinguished set of generators. We use
this correspondence to characterize the
expressive power of Lindstr{\"o}m quantifiers
associated with a class of regular languages",
}

@techreport{BRICS-RS-03-27,
author = 	 "Aceto, Luca and Fokkink, Willem Jan and van
Glabbeek, Rob J. and Ing{\'o}lfsd{\'o}ttir,
Anna",
title = 	 "Nested Semantics over Finite Trees are
Equationally Hard",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-27",
month = 	 aug,
note = 	 "31~pp",
abstract = 	 "This paper studies nested simulation and
nested trace semantics over the language BCCSP,
a basic formalism to express finite process
behaviour. It is shown that none of these
semantics affords finite (in)equational
axiomatizations over BCCSP. In particular, for
each of the nested semantics studied in this
paper, the collection of sound, closed
(in)equations over a singleton action set is
not finitely based",
}

@techreport{BRICS-RS-03-26,
author = 	 "Danvy, Olivier and Schultz, Ulrik P.",
title = 	 "Lambda-Lifting in Quadratic Time",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-26",
month = 	 aug,
note = 	 "23~pp. Extended version of a paper appearing
in " # lncs2441 # ", pages 134--151. This
report supersedes the earlier BRICS report
RS-02-30",
abstract = 	 "Lambda-lifting is a program transformation
used in compilers and in partial evaluators and
we show how to reduce this complexity to
quadratic time, and we present a flow-sensitive
lambda-lifter that also works in quadratic
time.\bibpar
Lambda-lifting transforms a block-structured
program into a set of recursive equations, one
for each local function in the source program.
Each equation carries extra parameters to
account for the free variables of the
corresponding local function {\em and of all
its callees}. It is the search for these extra
parameters that yields the cubic factor in the
which is due to Johnsson. This search is
carried out by a transitive closure.\bibpar
Instead, we partition the call graph of the
source program into strongly connected
components, based on the simple observation
that {\em all functions in each component need
the same extra parameters and thus a transitive
closure is not needed}. We therefore simplify
the search for extra parameters by treating
each strongly connected component instead of
each function as a unit, thereby reducing the
time complexity of lambda-lifting from ${\cal O}(n^3\log n)$ to ${\cal O}(n^2\log n)$, where
$n$ is the size of the program.\bibpar
Since a lambda-lifter can output programs of
size ${\cal O}(n^2)$, we believe that our
algorithm is close to optimal.",
}

@techreport{BRICS-RS-03-25,
author =	 "Dariusz, Biernacki and Olivier, Danvy",
title =	 "From Interpreter to Logic Engine by
Defunctionalization",
institution =	 brics,
year =	 2003,
type =	 rs,
number =	 "RS-03-25",
month =	 jun,
note =	 "13~pp. Presented at the International Symposium on
Logic Based Program Development and Transformation,
LOPSTR 2003, Uppsala, Sweden, August 25--27,
2003. This report is superseded by the later report
RS-04-5}{http://www.brics.dk/RS/04/5/}",
abstract =	 "Starting from a continuation-based interpreter for a
simple logic programming language, propositional
Prolog with cut, we derive the corresponding logic
engine in the form of an abstract machine. The
derivation originates in previous work (our article
at PPDP 2003) where it was applied to the
lambda-calculus. The key transformation here is
Reynolds's defunctionalization that transforms a
tail-recursive, continuation-passing interpreter
into a transition system, i.e., an abstract
machine. Similar denotational and operational
semantics were studied by de Bruin and de Vink in
previous work (their article at TAPSOFT 1989), and
we compare their study with our
derivation. Additionally, we present a direct-style
interpreter of propositional Prolog expressed with
control operators for delimited continuations.",
}

@techreport{BRICS-RS-03-24,
author = 	 "Ager, Mads Sig and Danvy, Olivier and
Midtgaard, Jan",
title = 	 "A Functional Correspondence between
Call-by-Need Evaluators and Lazy Abstract
Machines",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-24",
month = 	 jun,
note = 	 "13~pp. This report is superseded by the later
RS-04-3}{http://www.brics.dk/RS/04/3/}",
abstract = 	 "We bridge the gap between compositional
evaluators and abstract machines for the
lambda-calculus, using closure conversion,
transformation into continuation-passing style,
and defunctionalization of continuations. This
article is a spin-off of our article at PPDP
2003, where we consider call by name and call
by value. Here, however, we consider call by
need.\bibpar
We derive a lazy abstract machine from an
ordinary call-by-need evaluator that threads a
heap of updatable cells. In this resulting
abstract machine, the continuation fragment for
updating a heap cell naturally appears as an
update marker', an implementation technique
that was invented for the Three Instruction
Machine and subsequently used to construct lazy
variants of Krivine's abstract machine. Tuning
the evaluator leads to other implementation
techniques such as unboxed values and the
push-enter model. The correctness of the
resulting abstract machines is a corollary of
the correctness of the original evaluators and
of the program transformations used in the
derivation.",
}

@techreport{BRICS-RS-03-23,
author = 	 "Korovina, Margarita",
title = 	 "Recent Advances in $\Sigma$-definability over
Continuous Data Types",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-23",
month = 	 jun,
note = 	 "24~pp",
abstract = 	 "The purpose of this paper is to survey our
recent research in computability and
definability over continuous data types such as
the real numbers, real-valued functions and
functionals. We investigate the expressive
power and algorithmic properties of the
language of $\Sigma$-formulas intended to
represent computability over the real numbers.
In order to adequately represent computability
we extend the reals by the structure of
hereditarily finite sets. In this setting it is
crucial to consider the real numbers without
equality since the equality test is undecidable
over the reals. We prove Engeler's Lemma for
$\Sigma$-definability over the reals without
the equality test which relates $\Sigma$-definability with definability in the
constructive infinitary language $L_{\omega_1 \omega}$. Thus, a relation over the real
numbers is $\Sigma$-definable if and only if it
is definable by a disjunction of a recursively
enumerable set of quantifier free formulas.
This result reveals computational aspects of
$\Sigma$-definability and also gives
topological characterisation of $\Sigma$-definable relations over the reals without
the equality test. We also illustrate how
computability over the real numbers can be
expressed in the language of $\Sigma$-formulas",
}

@techreport{BRICS-RS-03-22,
author = 	 "Damg{\aa}rd, Ivan B. and Jurik, Mads J.",
title = 	 "Scalable Key-Escrow",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-22",
month = 	 may,
note = 	 "15~pp",
abstract = 	 "We propose a cryptosystem that has an inherent
key escrow mechanism. This leads us to propose
a session based public verifiable key escrow
system that greatly improves the amount of key
material the escrow servers has to keep in
order to decrypt an encryption. In our scheme
the servers will only have a single secret
sharing, as opposed to a single key from every
escrowed player. This is done while still
having the properties: 1) public verifiable:
the user proves to everyone that the encryption
can indeed be escrowed, and 2) no secret
leakage: no matter how many decryptions a law
enforcement agency is presented, it will gain
than it couldn't have calculated itself",
}

@techreport{BRICS-RS-03-21,
author = 	 "Kohlenbach, Ulrich",
title = 	 "Some Logical Metatheorems with Applications in
Functional Analysis",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-21",
month = 	 may,
note = 	 "55~pp. Slighly revised and extended version to
appear in {\em Transactions of the American
Mathematical Society}",
keywords = 	 "Proof mining, functionals of finite type,
convex analysis, fixed points, nonexpansive
mappings, hyperbolic spaces",
abstract = 	 "In previous papers we have developed
proof-theoretic techniques for extracting
effective uniform bounds from large classes of
ineffective existence proofs in functional
analysis. Uniform' here means independence
from parameters in compact spaces. A recent
case study in fixed point theory systematically
yielded uniformity even w.r.t.\
parameters in
metrically bounded (but noncompact) subsets
which had been known before only in special
cases. In the present paper we prove general
logical metatheorems which cover these
applications to fixed point theory as special
cases but are not restricted to this area at
all. Our theorems guarantee under general
logical conditions such strong uniform versions
of non-uniform existence statements. Moreover,
they provide algorithms for actually extracting
effective uniform bounds and transforming the
original proof into one for the stronger
uniformity result. Our metatheorems deal with
general classes of spaces like metric spaces,
hyperbolic spaces, normed linear spaces,
uniformly convex spaces as well as inner
product spaces.",
}

@techreport{BRICS-RS-03-20,
author = 	 "Ager, Mads Sig and Danvy, Olivier and Rohde,
Henning Korsholm",
title = 	 "Fast Partial Evaluation of Pattern Matching in
Strings",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-20",
month = 	 may,
note = 	 "16~pp. Final version in " # acmpepm03 # ",
pages 3--9. This report supersedes the earlier
BRICS report RS-03-11",
abstract = 	 "We show how to obtain all of Knuth, Morris,
and Pratt's linear-time string matcher by
partial evaluation of a quadratic-time string
matcher with respect to a pattern string.
Although it has been known for 15 years how to
obtain this linear matcher by partial
evaluation of a quadratic one, how to obtain it
{\em in linear time} has remained an open
problem.\bibpar
Obtaining a linear matcher by partial
evaluation of a quadratic one is achieved by
performing its backtracking at specialization
time and memoizing its results. We show (1) how
to rewrite the source matcher such that its
static intermediate computations can be shared
at specialization time and (2) how to extend
the memoization capabilities of a partial
evaluator to static functions. Such an extended
partial evaluator, if its memoization is
implemented efficiently, specializes the
rewritten source matcher in linear time",
}
@techreport{BRICS-RS-03-19,
author = 	 "Kirkegaard, Christian and M{\o}ller, Anders
and Schwartzbach, Michael I.",
title = 	 "Static Analysis of {XML} Transformations in
Java",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-19",
month = 	 may,
note = 	 "29~pp",
abstract = 	 "XML documents generated dynamically by
programs are typically represented as text
strings or DOM trees. This is a low-level
approach for several reasons: 1) Traversing and
modifying such structures can be tedious and
error prone; 2) Although schema languages,
e.g.\ DTD, allow classes of XML documents to be
defined, there are generally no automatic
mechanisms for statically checking that a
program transforms from one class to another as
intended.

We introduce {\sc Xact}, a high-level approach
for Java using XML templates as a first-class
data type with operations for manipulating XML
values based on XPath. In addition to an
efficient runtime representation, the data type
permits static type checking using DTD schemas
as types. By specifying schemas for the input
and output of a program, our algorithm will
statically verify that valid input data is
always transformed into valid output data and
that no errors occur during processing",
}

@techreport{BRICS-RS-03-18,
author = 	 "Klin, Bartek and Soboci{\'n}ski, Pawe{\l}",
Approach to Process Equivalence",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-18",
month = 	 apr,
note = 	 "41~pp. Appears in " # lncs2761 # ", pages
72--86",
abstract = 	 "A framework of Plotkin and Turis, originally
aimed at providing an abstract notion of
bisimulation, is modified to cover other
operational equivalences and preorders.
Combined with bialgebraic methods, it yields a
technique for deriving syntactic formats for
transition system specifications, which
guarantee operational preorders to be
precongruences. The technique is applied to the
trace prorder, the completed trace preorder and
the failures preorder. In the latter two cases,
new syntactic formats guaranteeing
precongruence properties are introduced",
}
@techreport{BRICS-RS-03-17,
author = 	 "Aceto, Luca and Hansen, Jens Alsted and
Ing{\'o}lfsd{\'o}ttir, Anna and Johnsen, Jacob
and Knudsen, John",
title = 	 "The Complexity of Checking Consistency of
{P}edigree Information and Related Problems",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-17",
month = 	 mar,
note = 	 "31~pp. This paper supersedes BRICS Report
RS-02-42",
abstract = 	 "{Consistency checking} is a fundamental
computational problem in genetics. Given a
pedigree and information on the genotypes (of
some) of the individuals in it, the aim of
consistency checking is to determine whether
these data are consistent with the classic
Mendelian laws of inheritance. This problem
arose originally from the geneticists' need to
filter their input data from erroneous
information, and is well motivated from both a
biological and a sociological viewpoint. This
paper shows that consistency checking is
NP-complete, even with focus on a single gene
and in the presence of three alleles. Several
other results on the computational complexity
of problems from genetics that are related to
consistency checking are also offered. In
particular, it is shown that checking the
consistency of pedigrees over two alleles, and
of pedigrees without loops, can be done in
polynomial time",
}

@techreport{BRICS-RS-03-16,
author = 	 "Damg{\aa}rd, Ivan B. and Jurik, Mads J.",
title = 	 "A Length-Flexible Threshold Cryptosystem with
Applications",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-16",
month = 	 mar,
note = 	 "31~pp",
keywords = 	 "length-flexible, length-invariant, mix-net,
group decryption, self-tallying, election,
perfect ballot secrecy",
abstract = 	 "We propose a public-key cryptosystem which is
derived from the Paillier cryptosystem. The
scheme inherits the attractive homomorphic
properties of Paillier encryption. In addition,
we achieve two new properties: First, all users
can use the same modulus when generating key
pairs, this allows more efficient proofs of
relations between different encryptions.
Second, we can construct a threshold decryption
protocol for our scheme that is length
flexible, i.e., it can handle efficiently
messages of arbitrary length, even though the
public key and the secret key shares held by
decryption servers are of fixed size. We show
how to apply this cryptosystem to build:\bibpar

1) a self-tallying election scheme with perfect
ballot secrecy. This is a small voting system
where the result can be computed from the
submitted votes without the need for decryption
servers. The votes are kept secret unless the
cryptosystem can be broken, regardless of the
number of cheating parties. This is in contrast
to other known schemes that usually require a
number of decryption servers, the majority of
which must be honest.\bibpar

2) a length-flexible mix-net which is
universally verifiable, where the size of keys
and ciphertexts do not depend on the number of
mix servers, and is robust against a corrupt
minority. Mix-nets can provide anonymity by
shuffling messages to provide a random
permutation of input ciphertexts to the output
plaintexts such that no one knows which
plaintexts relate to which ciphertexts. The
mix-net inherits several nice properties from
the underlying cryptosystem, thus making it
useful for a setting with small messages or
high computational power, low-band width and
that anyone can verify that the mix have been
done correctly",
}

@techreport{BRICS-RS-03-15,
author = 	 "Ing{\'o}lfsd{\'o}ttir, Anna",
title = 	 "A Semantic Theory for Value--Passing Processes
Based on the Late Approach",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-15",
month = 	 mar,
note = 	 "48~pp",
abstract = 	 "A general class of languages for value-passing
calculi based on the late semantic approach is
defined and a concrete instantiation of the
general syntax is given. This is a modification
of the standard $CCS$ according to the late
approach. Three kinds of semantics are given
for this language. First a Plotkin style
operational semantics by means of an
applicative labelled transition system is
introduced. This is a modification of the
standard labelled transition system that caters
for value-passing according to the late
approach. As an abstraction, late bisimulation
preorder is given. Then a general class of
denotational models for the late semantics is
defined. A denotational model for the concrete
language is given as an instantiation of the
general class. Two equationally based proof
systems are defined. The first one, which is
finite number of values at each time, is shown
to be sound and complete with respect to this
model. The second proof system, a
value-infinitary one, is shown to be sound with
respect to the model, whereas the completeness
is proven later. The operational and the
denotational semantics are compared and it is
shown that the bisimulation preorder is finer
than the preorder induced by the denotational
model. We also show that in general the $\omega$-bisimulation preorder is strictly included in
the model induced preorder. Finally a
value-finitary version of the bisimulation
preorder is defined and the full abstractness
of the denotational model with respect to it is
shown. It is also shown that for $CCS_L$ the
$\omega$-bisimulation preorder coincides with
the preorder induced by the model. From this we
can conclude that if we allow for parameterized
recursion in our language, we may express
processes which coincide in any algebraic
domain but are distinguished by the $\omega$-bisimulation. This shows that if we extend
$CCS_L$ in this way we obtain a strictly more
expressive language",
}

@techreport{BRICS-RS-03-14,
author = 	 "Ager, Mads Sig and Biernacki, Dariusz and
Danvy, Olivier and Midtgaard, Jan",
title = 	 "From Interpreter to Compiler and Virtual
Machine: A Functional Derivation",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-14",
month = 	 mar,
note = 	 "36~pp",
abstract = 	 "We show how to derive a compiler and a virtual
machine from a compositional interpreter. We
first illustrate the derivation with two
evaluation functions and two normalization
functions. We obtain Krivine's machine,
Felleisen et al.'s CEK machine, and a
generalization of these machines performing
strong normalization, which is new. We observe
that several existing compilers and virtual
machines---e.g., the Categorical Abstract
Machine (CAM), Schmidt's VEC machine, and
Leroy's Zinc abstract machine---are already in
derived form and we present the corresponding
interpreter for the CAM and the VEC machine. We
also consider Hannan and Miller's CLS machine
and Landin's SECD machine.\bibpar
We derived Krivine's machine via a call-by-name
CPS transformation and the CEK machine via a
call-by-value CPS transformation. These two
derivations hold both for an evaluation
function and for a normalization function. They
provide a non-trivial illustration of
Reynolds's warning about the evaluation order
of a meta-language",
}

@techreport{BRICS-RS-03-13,
author = 	 "Ager, Mads Sig and Biernacki, Dariusz and
Danvy, Olivier and Midtgaard, Jan",
title = 	 "A Functional Correspondence between Evaluators
and Abstract Machines",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-13",
month = 	 mar,
note = 	 "28~pp",
abstract = 	 "We bridge the gap between functional
evaluators and abstract machines for the
lambda-calculus, using closure conversion,
transformation into continuation-passing style,
and defunctionalization of
continuations.\bibpar
We illustrate this bridge by deriving Krivine's
abstract machine from an ordinary call-by-name
evaluator and by deriving an ordinary
call-by-value evaluator from Felleisen et al.'s
CEK machine. The first derivation is strikingly
simpler than what can be found in the
literature. The second one is new. Together,
they show that Krivine's abstract machine and
the CEK machine correspond to the call-by-name
and call-by-value facets of an ordinary
evaluator for the lambda-calculus.\bibpar
We then reveal the denotational content of
Hannan and Miller's CLS machine and of Landin's
SECD machine. We formally compare the
corresponding evaluators and we illustrate some
relative degrees of freedom in the design
spaces of evaluators and of abstract machines
for the lambda-calculus with computational
effects.\bibpar
For the purpose of this work, we distinguish
between virtual machines, which have an
instruction set, and abstract machines, which
do not. The Categorical Abstract Machine, for
example, has an instruction set, but Krivine's
machine, the CEK machine, the CLS machine, and
the SECD machine do not; they directly operate
on lambda-terms instead. We present the
abstract machine that corresponds to the
Categorical Abstract Machine",
}

@techreport{BRICS-RS-03-12,
author = 	 "Hernest, Mircea-Dan and Kohlenbach, Ulrich",
title = 	 "A Complexity Analysis of Functional
Interpretations",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-12",
month = 	 feb,
note = 	 "70~pp",
abstract = 	 "We give a quantitative analysis of G{\"o}del's
functional interpretation and its monotone
variant. The two have been used for the
extraction of programs and numerical bounds as
well as for conservation results. They apply
both to (semi-)intuitionistic as well as
(combined with negative translation) classical
proofs. The proofs may be formalized in systems
ranging from weak base systems to arithmetic
and analysis (and numerous fragments of these).
We give upper bounds in basic proof data on the
depth, size, maximal type degree and maximal
type arity of the extracted terms as well as on
the depth of the verifying proof. In all cases
terms of size linear in the size of the proof
at input can be extracted and the corresponding
extraction algorithms have cubic worst-time
complexity. The verifying proofs have depth
linear in the depth of the proof at input and
the maximal size of a formula of this proof",
}

@techreport{BRICS-RS-03-11,
author = 	 "Ager, Mads Sig and Danvy, Olivier and Rohde,
Henning Korsholm",
title = 	 "Fast Partial Evaluation of Pattern Matching in
Strings",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-11",
month = 	 feb,
note = 	 "14~pp. This report is superseded by the later
RS-03-20}{http://www.brics.dk/RS/03/20/}",
abstract = 	 "We show how to obtain all of Knuth, Morris,
and Pratt's linear-time string matcher by
partial evaluation of a quadratic-time string
matcher with respect to a pattern string.
Although it has been known for 15 years how to
obtain this linear matcher by partial
evaluation of a quadratic one, how to obtain it
{\em in linear time} has remained an open
problem.\bibpar
Obtaining a linear matcher by partial
evaluation of a quadratic one is achieved by
performing its backtracking at specialization
time and memoizing its results. We show (1) how
to rewrite the source matcher such that its
static intermediate computations can be shared
at specialization time and (2) how to extend
the memoization capabilities of a partial
evaluator to static functions. Such an extended
partial evaluator, if its memoization is
implemented efficiently, specializes the
rewritten source matcher in linear time"
}

@techreport{BRICS-RS-03-10,
author = 	 "Crazzolara, Federico and Milicia, Giuseppe",
title = 	 "Wireless Authentication in $\chi$-Spaces",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-10",
month = 	 feb,
note = 	 "20~pp",
abstract = 	 "The $\chi$-Spaces framework provides a set of
tools to support every step of the security
protocol's life-cycle. The framework includes a
simple, yet powerful programming language which
is an implementation of the Security Protocol
Language (SPL). SPL is a formal calculus
designed to model security protocols and prove
interesting properties about them. In this
paper we take an authentication protocol suited
for low-power wireless devices and derive a
$\chi$-Spaces implementation from its SPL
model. We study the correctness of the
resulting implementation using the underlying
SPL semantics of $\chi$-Spaces",
}

@techreport{BRICS-RS-03-9,
author = 	 "Damg{\aa}rd, Ivan B. and Frandsen, Gudmund
Skovbjerg",
title = 	 "An Extended Quadratic {F}robenius Primality
Test with Average and Worst Case Error
Estimates",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-9",
month = 	 feb,
note = 	 "53~pp. Appears in " # lncs2751 # ", pages
118--131",
abstract = 	 "We present an Extended Quadratic Frobenius
Primality Test (EQFT), which is related to the
Miller-Rabin test and the Quadratic Frobenius
test (QFT) by Grantham. EQFT takes time about
equivalent to 2 Miller-Rabin tests, but has
much smaller error probability, namely
$256/331776^t$ for $t$ iterations of the test
in the worst case. EQFT extends QFT by
related to the existence of elements of order
dividing 24. We also give bounds on the
average-case behaviour of the test: consider
the algorithm that repeatedly chooses random
odd $k$ bit numbers, subjects them to $t$
iterations of our test and outputs the first
one found that passes all tests. We obtain
numeric upper bounds for the error probability
of this algorithm as well as a general closed
expression bounding the error. For instance, it
is at most $2^{-143}$ for $k=500$",
}
@techreport{BRICS-RS-03-8,
author = 	 "Damg{\aa}rd, Ivan B. and Frandsen, Gudmund
Skovbjerg",
title = 	 "Efficient Algorithms for {gcd} and Cubic
Residuosity in the Ring of {E}isenstein
Integers",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-8",
month = 	 feb,
note = 	 "11~pp. Appears in " # lncs2751 # ", pages
109--117",
abstract = 	 "We present simple and efficient algorithms for
computing gcd and cubic residuosity in the ring
of Eisenstein integers, ${\bf Z}[\zeta]$, i.e.
the integers extended with $\zeta$, a complex
primitive third root of unity. The algorithms
are similar and may be seen as generalisations
of the binary integer gcd and derived Jacobi
symbol algorithms. Our algorithms take time
$O(n^2)$ for $n$ bit input. This is an
improvement from the known results based on the
Euclidian algorithm, and taking time $O(n\cdot M(n))$, where $M(n)$ denotes the complexity of
multipliplying $n$ bit integers. The new
algorithms have applications in practical
primality tests and the implementation of
cryptographic protocols. The technique
underlying our algorithms can be used to obtain
equally fast algorithms for gcd and quartic
residuosity in the ring of Gaussian integers,
${\bf Z}[i]$",
}
@techreport{BRICS-RS-03-7,
author = 	 "Brabrand, Claus and Schwartzbach, Michael I.
title = 	 "The {METAFRONT} System: Extensible Parsing and
Transformation ",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-7",
month = 	 feb,
note = 	 "24~pp",
abstract = 	 "We present the metafront tool for specifying
flexible, safe, and efficient syntactic
transformations between languages defined by
context-free grammars. The transformations are
guaranteed to terminate and to map
grammatically legal input to grammatically
legal output.\bibpar

We rely on a novel parser algorithm that is
designed to support gradual extensions of a
grammar by allowing productions to remain in a
natural style and by statically reporting
ambiguities and errors in terms of individual
productions as they are being added.\bibpar

Our tool may be used as a parser generator in
which the resulting parser automatically
supports a flexible, safe, and efficient macro
processor, or as an extensible lightweight
compiler generator for domain-specific
languages. We show substantial examples of both
kinds. ",
}

@techreport{BRICS-RS-03-6,
author = 	 "Milicia, Giuseppe and Sassone, Vladimiro",
title = 	 "Jeeg: Temporal Constraints for the
Synchronization of Concurrent Objects",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-6",
month = 	 feb,
note = 	 "41~pp. Short version appears in " # acmjgi02 #
", pages 212--221",
abstract = 	 "We introduce Jeeg, a dialect of Java based on
a declarative replacement of the
synchronization mechanisms of Java that results
in a complete decoupling of the business' and
the synchronization' code of classes.
Synchronization constraints in Jeeg are
expressed in a linear temporal logic which
allows to effectively limit the occurrence of
the inheritance anomaly that commonly affects
concurrent object oriented languages. Jeeg is
inspired by the current trend in aspect
oriented languages. In a Jeeg program the
sequential and concurrent aspects of object
behaviors are decoupled: specified separately
by the programmer these are then weaved
together by the Jeeg compiler",
}

@techreport{BRICS-RS-03-5,
author = 	 "Christensen, Aske Simon and M{\o}ller, Anders
and Schwartzbach, Michael I.",
title = 	 "Precise Analysis of String Expressions",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-5",
month = 	 feb,
note = 	 "15~pp",
abstract = 	 "We perform static analysis of Java programs to
answer a simple question: which values may
occur as results of string expressions? The
answers are summarized for each expression by a
regular language that is guaranteed to contain
all possible values. We present several
applications of this analysis, including
statically checking the syntax of dynamically
generated expressions, such as SQL queries. Our
analysis constructs flow graphs from class
files and generates a context-free grammar with
a nonterminal for each string expression. The
language of this grammar is then widened into a
regular language through a variant of an
algorithm previously used for speech
recognition. The collection of resulting
regular languages is compactly represented as a
special kind of multi-level automaton from
which individual answers may be extracted. If a
program error is detected, examples of invalid
strings are automatically produced. We present
extensive benchmarks demonstrating that the
analysis is efficient and produces results of
useful precision",
}

@techreport{BRICS-RS-03-4,
author = 	 "Carbone, Marco and Nielsen, Mogens and
title = 	 "A Formal Model for Trust in Dynamic Networks",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-4",
month = 	 jan,
note = 	 "18~pp. Appears in " # ieeesefm03 # ", pages
54--61",
abstract = 	 "We propose a formal model of trust informed by
the Global Computing scenario and focusing on
the aspects of trust formation, evolution, and
propagation. The model is based on a novel
notion of trust structures which, building on
concepts from trust management and domain
theory, feature at the same time a trust and an
information partial order",
}
@techreport{BRICS-RS-03-3,
author = 	 "Cr{\'e}peau, Claude and Dumais, Paul and
Mayers, Dominic and Salvail, Louis",
title = 	 "On the Computational Collapse of Quantum
Information",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-3",
month = 	 jan,
note = 	 "31~pp",
keywords = 	 "quantum bit commitment, oblivious transfer,
quantum measurement, computational
assumptions",
abstract = 	 "We analyze the situation where computationally
binding string commitment schemes are used to
force the receiver of a BB84 encoding of a
classical bitstring to measure upon reception.
Since measuring induces an irreversible
collapse to the received quantum state, even
given extra information after the measurement
does not allow the receiver to evaluate
reliably some predicates apply to the classical
bits encoded in the state. This fundamental
quantum primitive is called quantum measure
commitment (QMC) and allows for secure
two-party computation of classical functions.
An adversary to QMC is one that can both
provide valid proof of having measured the
received states while still able to evaluate a
predicate applied to the classical content of
the encoding. We give the first quantum
black-box reduction for the security of QMC to
the binding property of the string commitment.
We characterize a class of quantum adversaries
against QMC that can be transformed into
adversaries against a weak form for the binding
property of the string commitment. Our result
provides a construction for $1-2$-oblivious
transfer that is computationally secure against
the receiver and unconditionally secure against
the sender from any string commitment scheme
satisfying a weak binding property ",
}

@techreport{BRICS-RS-03-2,
author = 	 "Danvy, Olivier and L{\'o}pez, Pablo E.
Mart{\'\i}nez",
title = 	 "Tagging, Encoding, and {J}ones Optimality",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-2",
month = 	 jan,
note = 	 "Appears in " # lncs2618 # ", pages 335--347",
abstract = 	 "A partial evaluator is said to be
Jones-optimal if the result of specializing a
self-interpreter with respect to a source
program is textually identical to the source
program, modulo renaming. Jones optimality has
already been obtained if the self-interpreter
is untyped. If the self-interpreter is typed,
however, residual programs are cluttered with
type tags. To obtain the original source
program, these tags must be removed.\bibpar
A number of sophisticated solutions have
already been proposed. We observe, however,
that with a simple representation shift,
Jones-optimal, modulo an encoding. The
representation shift amounts to reading the
type tags as constructors for higher-order
abstract syntax. We substantiate our
observation by considering a typed
self-interpreter whose input syntax is
higher-order. Specializing this interpreter
with respect to a source program yields a
residual program that is textually identical to
the source program, modulo renaming",
}

@techreport{BRICS-RS-03-1,
author = 	 "Sassone, Vladimiro and Sobocinski, Pawe{\l}",
title = 	 "Deriving Bisimulation Congruences:
2-Categories vs.\
Precategories",
institution =  brics,
year = 	 2003,
type = 	 rs,
number = 	 "RS-03-1",
month = 	 jan,
note = 	 "28~pp. Appears in " # lncs2620 # ", pages
409--424",
abstract = 	 "G-relative pushouts (GRPOs) have recently been
proposed by the authors as a new foundation for
Leifer and Milner's approach to deriving
labelled bisimulation congruences from
reduction systems. This paper develops the
theory of GRPOs further, arguing that they
provide a simple and powerful basis towards a
comprehensive solution. As an example, we
construct GRPOs in a category of bunches and
wirings.' We then examine the approach based on
Milner's precategories and Leifer's functorial
reactive systems, and show that it can be
recast in a much simpler way into the
2-categorical theory of GRPOs",
`