Well-structured transition systems (WSTSs) are a general class of infinite-state systems for
which decidability results rely on the existence of a well-quasi-ordering between states that …

Programming-by-Examples (PBE) involves synthesizing an" intended program" from a small
set of user-provided input-output examples. A key PBE strategy has been to restrict the …

We present a structure for transition systems with which the main decidability results on Petri
nets can be generalized to structured transition systems. We define the reduced reachability …

We introduce a hierarchy of fast-growing complexity classes and show its suitability for
completeness statements of many nonelementary problems. This hierarchy allows the …

String analysis is the problem of reasoning about how strings are manipulated by a program.
It has numerous applications including automatic detection of cross-site scripting, and …

Fast acceleration of symbolic transition systems (F ast) is a tool for the analysis of systems
manipulating unbounded integer variables. We check safety properties by computing the …

Well-structured systems, aka WSTS, are computational models where the set of possible
configurations is equipped with a well-quasi-ordering which is compatible with the transition …

We describe a simple, conceptual forward analysis procedure for infinity-complete WSTS S.
This computes the so-called clover of a state. When S is the completion of a WSTS X, the …

In this paper, we give a step by step introduction to the theory of well quasi-ordered
transition systems. The framework combines two concepts, namely (i) transition systems …

In this paper, we develop a unified approach for deriving complexity results for a number of
Petri net problems. We first define a class of formulas for paths in Petri nets. We then show …