Boolean complexity

• 2026-08-28 [Verified] Geometry under-determines Boolean complexity at dim = 4: bang dim 4, code 27 and bang dim 4, code 281 share genus, GF(2) degree, popcount and the fill polynomial 4k^4 - 4k^3 + k^2 and split six of seven complexity measures; across the 424 classes (22 + 402) 92 groups hold two or more classes and 279 measure splits occur. Witness: lab/py/boolean-measures, mrlymath::bang::counting::sequence.
• 2026-08-28 [Verified] Sensitivity and block sensitivity separate exactly once in the dim <= 4 catalog: s = bs on all 22 classes at dim = 3 and on 401 of 402 at dim = 4, the exception bang dim 4, code 7128 with s = 2, bs = 3, orbit 24; C = bs on all 424 classes; exactly two classes meet deg = s^2, bang dim 4, code 855 and bang dim 4, code 1911, the second the AND-of-ORs that Huang 2019 names tight for s(f) >= sqrt(deg(f)). Witness: lab/py/boolean-measures.