The model contains one compartment called C. There are four species called S1, S2, S3 and S4 and three parameters called k1, k2 and p1. The model contains one reaction defined as:

Reaction Rate
S1 → S2 k1 · S1 · C

The model contains two rules:

Type Variable Formula
Rate S3 k2 · S4
Rate S4 −k2 · S4

The model contains one initialAssignment:

Variable Formula
S1 p10.5

Note: InitialAssignments override any declared initial values. In this case the value of species S1 calculated by the initialAssignment is inconsisent with the value declared by the model definition. The calculated value should be used.

The initial conditions are as follows:

Value Units
Initial amount of S1 0 mole
Initial amount of S2 2.0 mole
Initial amount of S3 1.5 mole
Initial amount of S4 4 mole
Value of parameter k1 0.75 second-1
Value of parameter k2 0.25 second-1
Value of parameter p 0.75 mole litre-1
Volume of compartment C 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.