The model contains one compartment called C. There are three species called S1, S2 and S3 and two parameters called k1 and k2. Compartment C is 0-dimensional. The model contains two reactions defined as:

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

The model contains one event that assigns values to both species S1 and S2:

Trigger Delay Assignments
Event1 S1 < 0.45 S2 = 1.25
S1 = 0.6

The initial conditions are as follows:

Value Units
Initial amount of S1 1.0 mole
Initial amount of S2 2.0 mole
Initial amount of S3 1.0 mole
Value of parameter k1 0.75 mole-1 second-1
Value of parameter k2 0.25 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.