Upper panels: effect of Lyα on the formation of the Hα line: initial Hα profile (black solid) and the profile from the models in which Lyα transitions were artificially removed (the red dash-dotted line). Middle panels: changes in the 2nd (dashed) and 3rd (solid) level of H due to the removal of Lyα in model C (left) and M (right). The plots present the ratio of the populations produced from the initial model over the populations from the models without Lyα transition. Lower panels: comparison of the net radiative rate of 2→1 transitions in the initial (solid black) and the model without Lyα (the red dash-dotted line) (see Sect. 3.4 for details).