Fig. 2
From: Enumeration of minimal stoichiometric precursor sets in metabolic networks
Illustration of facts 2–4. The stoichiometric values are all equal to one. There are two minimal TPSs: \(\{p1\}\) (obtained from the topological factory \(\{r_1,\ r_3,\ r_4\}\)), and \(\{p3\}\) (obtained from the topological factory \(\{r_7,\ r_6,\ r_5\}\)). The source p2 does not take part of a minimal topological factory because its consumption involves the consumption of the source p3, which forms already a minimal TPS. There are two minimal SPSs: \(\{p1\}\) (obtained from the stoichiometric factory \(\{r_1,\ r_2,\ r_3,\ r_4\}\)), and \(\{p2, p3\}\) (obtained from the stoichiometric factory \(\{r_8\}\))