Figure 2. Schematic illustration of the four sufficient conditions for sign determinedness, C1–C4.

The conditions are explained by means of example patterns that are either allowed or forbidden. Notice that the above examples are not meant to be exhaustive; their aim is simply to clarify the consequences of C1–C4 on a few concrete cases. In the examples, A, B, C, and E are proteins, while m₁, m₂, and m₃ are metabolites. is the concentration control coefficient of m₃ with respect to the reaction catalyzed by E.