Theorem: sigma(v) v - sigma_0 v_0 = 0 (1/v-law product invariance)

Theorem (1/v-product canonical): sigma(v) = sigma_0 v_0/v multiplied by v yields sigma(v) v = sigma_0 v_0 = constant. Residual: sigma(v) v - sigma_0 v_0 = 0 identically. Canonical sympy pin: sigma_0, v_0, v = sp.symbols('sigma_0 v_0 v',…