@TechReport{	  it:2000-021,
  author	= {Parosh Aziz Abdulla and Aletta Nyl{\'e}n},
  title		= {{BQO}s and Timed Petri Nets},
  institution	= {Department of Information Technology, Uppsala University},
  department	= {Division of Computer Systems},
  year		= {2000},
  number	= {2000-021},
  month		= aug,
  abstract	= {In this paper, we use the theory of better quasi-orderings
		  to define a methodology for inventing constraint systems
		  which are both well quasi-ordered and compact. We apply our
		  methodology by presenting new constraint systems for
		  verification of systems with unboundedly many real-valued
		  clocks, and use them for checking safety properties for
		  lazy (non-urgent) timed Petri nets where each token is
		  equipped with a real-valued clock.}
}