Tatjana Petrov ETH Zurich Title: Approximate reductions of rule-base models Abstract: In recent works, general algorithms for the exact reductions of rule-based models were established. However, in the stochastic setting, the reduced state space often remains combinatorially large. This is because preserving exactness demands complete independence between the dynamics over groups of proteins' domains (sites). We extend this line of research by introducing an error measure which allows us to quantitatively study the effect of approximate reductions of rule-based models, which can be seen as approximate probabilistic bisimulation. The error is introduced over point-wise probability distributions, and it is extended to the trace density semantics. We perform the analysis on a rule-based formalism in terms of site-graph-rewrite rules.