(0) A–C denote three speciess of chemicals in the system, 1,2–2,3,4 denote reactions, and the arrows denote state changes due to these reactions. (1–4) Response patterns to the increase in each reaction parameter in the chemical reaction system shown in (0). The results of structural sensitivity analysis (11) are graphically represented. The red arrowhead shows a perturbed reaction. Red letters indicate changes in molecular concentration. Red upper and lower cases denote increase and decrease in concentration, respectively. Red arrows indicate changes in reaction rate. Red bold and dotted arrows denote increase and decrease in reaction rate, respectively. Black letters and black arrows indicate unchanged concentrations of molecules and reactions, respectively.