13th International Conference on Membrane Computing - MTA Sztaki

Mobile membranes with objects on surface as colored Petri nets
Home Markings: [24] Dead Markings: [24];
Dead Transition Instances: None Live Transition Instances: None
Fairness Properties: No infinite occurrence sequences,
meaning that we always reach configuration M 24 (home marking), the computation
stops here (dead marking), and that there are no infinite occurrence
sequences.
The simulation of LDL degradation pathway is not entirely correct from a
biological point of view, because a cell is able to process more than one LDL
molecule. An arbitrary number of LDL molecules cannot be simulated by using
mobile membranes, but it can be simulated in colored Petri nets by adding a
new transition input and a new place applied as in Figure 7.
Fig. 7. LDL Degradation Pathway with input transition
In Figure 8 we show how the transition input is build, namely what are the
input arcs and output arcs together with their inscriptions.
Fig. 8. Input transition
This transition works as follows: if the cell has the initial structure less the
initial LDL molecule, then a new LDL molecule is added to the system in order
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