All four Maxwell equations derived from the foam wave equation □D = 0, the Helmholtz decomposition, and Volterra's theorem (1907). Charge quantisation from Oₕ lattice rotation discreteness (e/3, 2e/3, e). Charge conservation from winding number conservation. Gauge invariance from foam translational symmetry. Zero electromagnetic postulates. Zero free parameters.
Luke Martin (Mon,) studied this question.