ΔT_th, ΔR and Δa_ℓ, 0 from ℓ = 1 to ℓ_max = 6 for the EDGES profile of redshifted 21 cm line (summed in intensity with the CMB blackbody). Solid lines (or dots) correspond to positive (or negative) values. Red and green lines are essentially superimposed at any ℓ. Their difference, multiplied by a factor F to have values compatible with the adopted range, is displayed by the blue lines. Yellow lines refer to the nominal integration error quoted by the routine D01AJF, again multiplied by the factor F. See also the legend and the text.