Beer-Lambert: T_trans·10^A − 1 ≡ 0 (exact identity)

Closed-form polynomial identity of the Beer-Lambert law. Setting T_trans = 10^(−A) and evaluating T_trans·10^A yields exactly 1; residual sp.simplify(T_trans·10^A − 1) = 0 literally — no numerics. Additional pins: at A = 1…