Haber: t_eff=k/C; 2C halves t_eff; D(t)=C·t; exp-decay D(t)=C_0/λ·(1−e^{−λt}); D(∞)=C_0/λ

Sympy-exact symbolic witness of Haber's rule time-to-effect canonical form and the exponentially-decaying-exposure generalisation. Setup: C, t, k, λ, C_0 — all positive symbols. Time to effect for constant exposure: t_eff = k/C (sympy…