Sialylation: S(n,M)=n·M; 4·Neu5Ac=1164 Da; NeuGc−Neu5Ac=+16 Da; cleavage decrement=−M·k

Sympy-exact symbolic witness of the sialylation stoichiometric mass-shift canonical form and integer anchors for Neu5Ac / NeuGc / tetrasialic residues. Setup: M (per-unit residue mass), n (sialic-acid count), k (cleaved units) — all…