The model contains two varying parameters called S1 and S2 and two constant parameters called k1 and k2. (Note that indeed S1 and S2 are parameters and not species in this model.)

The model contains two rules:

Type Variable Formula
Rate S1 −k2 · S1
Rate S2 k2 · S1

The model contains one initialAssignment:

Variable Formula
S1 k1 · S2

Note: InitialAssignments override any declared initial values. In this case, the initial value of S1 has not been explicitly declared and must be calculated using the initialAssignment.

The initial conditions are as follows:

Value Units
Value of parameter S1 undeclared any
Value of parameter S2 2.0 × 10−1 same as S1
Value of parameter k1 0.75 dimensionless
Value of parameter k2 0.25 second-1