Schematic representation of a convex cone characterized by five extreme pathways. Extreme Pathways 1–5 (EP₁, EP₂, EP₃, EP₄, and EP₅) circumscribe the solution space for the three fluxes indicated (v_A, v_B, v_C). EP₄ lies in the plane formed by fluxes v_A and v_B. Consequently, flux v_Cdoes not participate in that extreme pathway. EP₃, EP₄, and EP₅ are all close and represent different uses of a network to achieve a similar overall result. All points within the convex cone can be described as a non-negative linear combination of the extreme pathways.