The model contains one compartment called C. There are four species called S1, S2, S3 and S4 and one parameter called k. The model contains two reactions defined as:
Reaction | Rate |
S1 + S2 → S3 | k · S1 · S2 · C |
S3 → S1 + S2 | k · S3 · C |
Reaction S1 + S2 → S3 defines one local parameter k which has a scope local to the defining reaction. Reaction S3 → S1 + S2 defines another (different) local parameter k.
The model contains one rule:
Type | Variable | Formula |
Assignment | S4 | multiply(k, S2) |
The model contains one FunctionDefinition defined as:
Id | Arguments | Formula |
multiply | x, y | x · y |
Note that in this case the initial value of the species S4 is not explicitly declared and must be calculated by the AssignmentRule.
The initial conditions are as follows:
Value | Units | |
Initial amount of S1 | 1.0 × 10−4 | mole |
Initial amount of S2 | 2.0 × 10−4 | mole |
Initial amount of S3 | 1.5 × 10−4 | mole |
Initial amount of S4 | undeclared | mole |
Value of parameter k | 0.75 | dimensionless |
Value of local parameter k (R1) | 0.75 × 104 | litre mole-1 second-1 |
Value of local parameter k (R2) | 0.25 × 10−2 | second-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.