The model contains one compartment called "compartment". There are three species named S1, S2 and S3 and two parameters named k1 and k2. Species S1 is labeled as an SBML boundary species. The model contains two reactions defined as:

Reaction | Rate
S1 + S2 → S3 | k1 · S1 · S2 · compartment
S3 → S1 + S2 | k2 · S3 · compartment

The initial conditions are as follows:

| Value | Units
Initial amount of S1 | 1.0 × 10−3 | mole
Initial amount of S2 | 2.0 × 10−3 | mole
Initial amount of S3 | 1.0 × 10−3 | mole
Value of parameter k1 | 0.75 | litre mole-1 second-1
Value of parameter k2 | 0.25 | second-1
Volume of compartment "compartment" | 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.

Note: The test data for this model was generated from an analytical solution of the system of equations.