isosceles: max |K - eps_formula| over 20000 random cases = 7.283063041541027e-14
K(delta) monotone violations (of 4000 random cases): 0 ; regimes sampled: {'both_out': 339, 'far_out_near_in': 925, 'const': 2736} ; max derivative-formula mismatch: 0
Hessian checks in the middle regime: 3278 samples; closed-form det >= 0 and matches finite differences; min f_tautau = 0.02452208800103596
moment-lemma calculus checks OK
