1,933 research outputs found
Verification of Timed Automata Using Rewrite Rules and Strategies
ELAN is a powerful language and environment for specifying and prototyping
deduction systems in a language based on rewrite rules controlled by
strategies. Timed automata is a class of continuous real-time models of
reactive systems for which efficient model-checking algorithms have been
devised. In this paper, we show that these algorithms can very easily be
prototyped in the ELAN system. This paper argues through this example that
rewriting based systems relying on rules and strategies are a good framework to
prototype, study and test rather efficiently symbolic model-checking
algorithms, i.e. algorithms which involve combination of graph exploration
rules, deduction rules, constraint solving techniques and decision procedures
Synthesizing Quantum-Circuit Optimizers
Near-term quantum computers are expected to work in an environment where each
operation is noisy, with no error correction. Therefore, quantum-circuit
optimizers are applied to minimize the number of noisy operations. Today,
physicists are constantly experimenting with novel devices and architectures.
For every new physical substrate and for every modification of a quantum
computer, we need to modify or rewrite major pieces of the optimizer to run
successful experiments. In this paper, we present QUESO, an efficient approach
for automatically synthesizing a quantum-circuit optimizer for a given quantum
device. For instance, in 1.2 minutes, QUESO can synthesize an optimizer with
high-probability correctness guarantees for IBM computers that significantly
outperforms leading compilers, such as IBM's Qiskit and TKET, on the majority
(85%) of the circuits in a diverse benchmark suite.
A number of theoretical and algorithmic insights underlie QUESO: (1) An
algebraic approach for representing rewrite rules and their semantics. This
facilitates reasoning about complex symbolic rewrite rules that are beyond the
scope of existing techniques. (2) A fast approach for probabilistically
verifying equivalence of quantum circuits by reducing the problem to a special
form of polynomial identity testing. (3) A novel probabilistic data structure,
called a polynomial identity filter (PIF), for efficiently synthesizing rewrite
rules. (4) A beam-search-based algorithm that efficiently applies the
synthesized symbolic rewrite rules to optimize quantum circuits.Comment: Full version of PLDI 2023 pape
An Analysis of Arithmetic Constraints on Integer Intervals
Arithmetic constraints on integer intervals are supported in many constraint
programming systems. We study here a number of approaches to implement
constraint propagation for these constraints. To describe them we introduce
integer interval arithmetic. Each approach is explained using appropriate proof
rules that reduce the variable domains. We compare these approaches using a set
of benchmarks. For the most promising approach we provide results that
characterize the effect of constraint propagation. This is a full version of
our earlier paper, cs.PL/0403016.Comment: 44 pages, to appear in 'Constraints' journa
- …