The model contains one compartment called "compartment". There are five species named S1, S2, S3, S4 and S5 and two parameters named k1 and k2. Compartment "compartment" is 0-dimensional. Species S5 is labeled as constant and therefore cannot be changed by rules or reactions. The model contains two reactions defined as:

Reaction Rate
S1 + S2 → S3 + S4 k1 · S1 · S2
S3 + S4 → S1 + S2 k2 · S3 · S4S5

The initial conditions are as follows:

Value Units
Initial amount of S1 1.0 × 10−6 mole
Initial amount of S2 1.5 × 10−6 mole
Initial amount of S3 2.0 × 10−6 mole
Initial amount of S4 0.5 × 10−6 mole
Initial amount of S5 1.0 × 10−6 mole
Value of parameter k1 1.3 × 106 mole-1 second-1
Value of parameter k2 0.3 mole-1 second-1

In this example the compartment has its spatialDimensions attribute set to zero; i.e., it represents a point and therefore cannot have size or units. The species values must be treated as amounts and not concentrations.