process P1 
{
  state a,b;
  init a;
  trans	a->b {guard true;},
	b->b {guard true;};
}

process Pltl 
{
  state qa,qb,qc,qd;
  init qa;
  accept qd;
  trans qa->qb {guard true;},
  	qb->qc {guard true;},
  	qc->qd {guard true;},
	qd->qa {guard true;};
	
}

system async property Pltl;
