Polyketide n=5 parity: C1-count = C2-count = 5; Σ (-1)^(k+1) = 0

Sympy-exact witness of the polyketide C1/C2 parity identity on an n = 5 acetate-unit chain (2n = 10 carbons total). Setup: even positions = {2, 4, 6, 8, 10} (C1-derived, 5 carbons); odd positions = {1, 3, 5, 7, 9} (C2-derived, 5 carbons);…