The model contains two compartments named compartment and compartment1. There are four species named S1, S2, S3 and S4 and three parameters named k1, k2 and k3. Compartment "compartment" contains species S1 and S2. Compartment "compartment"1 contains species S3 and S4. The model contains two reactions defined as:

Reaction Rate
S1 + S2 → S2 + S2 k1 · S1 · S2 · compartment
S2 → S3 k2 · (S2−S3) · compartment1

The first reaction occurs entirely in compartment "compartment", whereas the second reaction occurs between a species in "compartment" and a species in "compartment1".

The model contains one rule which assigns value to species S4:

Type Variable Formula
Assignment S4 k3 · S3

In this case the initial value declared for species S4 is consistent with that calculated by the assignmentRule. Note that since this assignmentRule must always remain true, it should be considered during simulation.

The initial conditions are as follows:

Value Units
Initial amount of S1 1.0 mole
Initial amount of S2 1.0 mole
Initial amount of S3 0 mole
Initial amount of S4 0 mole
Value of parameter k1 0.75 litre mole-1 second-1
Value of parameter k2 0.25 second-1
Value of parameter k2 0.25 dimensionless
Volume of compartment "compartment" 1 litre
Volume of compartment "compartment"1 1 litre

The species values are given as amounts of substance to make it easier to use the model in a discrete stochastic simulator, but (as per usual SBML principles) their symbols represent their values in concentration units where they appear in expressions.