 We can always form the quotient graph   using the largest bisimulation. Here is how this works, using G  from above as an example.    In  G/≡b, we would have three nodes, corresponding to the three  equivalence classes under the largest bisimulation;  let’s call these  classes   1, 2 and 3.   We put an arrow between  two of these  classes if some (every) element of the first has an  arrow to some element of the second.    In this way, we   construct the quotient.    Here is a picture of  G  again, along with its   quotient  G/≡b under the largest bisimulation: 