fig4

Figure 4. Conditional feature attribution and continuous venous responses. (A) Exact Shapley allocation of the original λ₂ gap; (B) Exact total-throughput Shapley shares across 48 compartmental formulations. Original and compartmental feature definitions differ and are specified in Methods; percentages are allocations within each model, not physiological effect sizes; (C and D) Continuous MCLV-SDC conductance grids for the eight-unit local model with cSDC and either deep-only drainage or an additional contralateral SIEV outlet. Other enhancement parameters are fixed at 1. Colors show total-throughput increase relative to MCLV = SDC = 0 within each outlet configuration. Under deep-only drainage with SDC = 0, superficial collector pressures are equal and MCLV carries no flow. Increasing SDC breaks this symmetry, allowing an additional MCLV contribution. The added contralateral outlet also changes collector pressures and the MCLV response. (B) uses the reference budgets; Supplementary Table 5 reports the budget controls. MCLV: Midline-crossing linking vein; SDC: superficial-to-deep connection; SIEV: superficial inferior epigastric vein.