---
res:
  bibo_abstract:
  - The task of a monitor is to watch, at run-time, the execution of a reactive system,
    and signal the occurrence of a safety violation in the observed sequence of events.
    While finite-state monitors have been studied extensively, in practice, monitoring
    software also makes use of unbounded memory. We define a model of automata equipped
    with integer-valued registers which can execute only a bounded number of instructions
    between consecutive events, and thus can form the theoretical basis for the study
    of infinite-state monitors. We classify these register monitors according to the
    number k of available registers, and the type of register instructions. In stark
    contrast to the theory of computability for register machines, we prove that for
    every k 1, monitors with k + 1 counters (with instruction set 〈+1, =〉) are strictly
    more expressive than monitors with k counters. We also show that adder monitors
    (with instruction set 〈1, +, =〉) are strictly more expressive than counter monitors,
    but are complete for monitoring all computable safety -languages for k = 6. Real-time
    monitors are further required to signal the occurrence of a safety violation as
    soon as it occurs. The expressiveness hierarchy for counter monitors carries over
    to real-time monitors. We then show that 2 adders cannot simulate 3 counters in
    real-time. Finally, we show that real-time adder monitors with inequalities are
    as expressive as real-time Turing machines.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Thomas
      foaf_name: Ferrere, Thomas
      foaf_surname: Ferrere
      foaf_workInfoHomepage: http://www.librecat.org/personId=40960E6E-F248-11E8-B48F-1D18A9856A87
    orcid: 0000-0001-5199-3143
  - foaf_Person:
      foaf_givenName: Thomas A
      foaf_name: Henzinger, Thomas A
      foaf_surname: Henzinger
      foaf_workInfoHomepage: http://www.librecat.org/personId=40876CD8-F248-11E8-B48F-1D18A9856A87
    orcid: 0000−0002−2985−7724
  - foaf_Person:
      foaf_givenName: Ege
      foaf_name: Saraç, Ege
      foaf_surname: Saraç
  bibo_doi: 10.1145/3209108.3209194
  bibo_volume: Part F138033
  dct_date: 2018^xs_gYear
  dct_identifier:
  - UT:000545262800041
  dct_language: eng
  dct_publisher: IEEE@
  dct_title: A theory of register monitors@
...