The values of error probability P_s of distinguishing whether a two-level atom is evolved by or initially in the ground (g, black square), excited (e, red dot), superposition (s, blue triangle), and maximally mixed (m, green star) states for Ω₁ = 4.0κ and (a) δ₁ = 0.1κ, (b) δ₁ = 0.5κ, (c) δ₁ = 1.5κ, and (d) δ₁ = 3.5κ.