Veri cation using static analysis often hinges on precise numeric invariants. Numeric domains of in nite height can infer these invariants, but require widening/narrowing which complicates the xpoint computation and is often too imprecise. As a consequence, several strategies have been proposed to prevent a precision loss during widening or to narrow in a smarter way. Most of these strategies a...

This paper introduces a scheme for data stream processing which is robust to batch duration. Streaming frameworks process streams in batches retrieved at fixed time intervals. In a common setting a pattern recognition algorithm is applied independently to each batch. Choosing the right time interval is tough — a pattern may not fit in an interval which is too short, but detection will be delaye...

Model checking of infinite state systems is undecidable, therefore, there are instances for which fixpoint computations used in infinite state model checkers do not converge. Given a widening operator one can compute an upper approximation of a least fixpoint in finite number of steps even if the least fixpoint is uncomputable. We present a widening operator for automata encoding integer sets. ...