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 S2 · k2−S1 · k1
Rate S2 S1 · k1−S2 · k2

The initial conditions are as follows:

Value Units
Value of parameter S1 1.5 × 10−2 any
Value of parameter S2 0 same as S1
Value of parameter k1 1 second-1
Value of parameter k2 0 second-1