The Petri nets that we introduced in Chapter 8 are often called place/transition nets, or P/T-nets for short. In a P/T-net, a token in a place may indicate that the condition associated with that place is satisfied. Tokens may also be seen as objects in a pool or resources in storage. When a place contains multiple tokens, however, these tokens are not distinguishable from each other. This often leads to a large size of model, because if you want to specify multiple objects differently, even if they are of the same type, you have to model each object as a token in a different place.