Poisson distribution with parameter 𝑎 𝑝 • 𝜏 is used to approximate the number of propagation steps occurring during 𝜏. These propagation steps are then updated in bulk by adding the corresponding chain lengths to the active radicals. Subsequently, the effects of the "critical" step are updated. 𝑡 = 𝑡 + 𝜏, one critical reaction happened based on 𝑟, and batch processing of propagation using vectorization operations; 7: until termination conditions are met.