Definition of the four phases of flare evolution in a single loop and the spatial distribution of various quantities along the loop (L = 2 × 10⁴ km) at fixed times. The flare heating duration is set to τ_heat = 204 s > τ_c (case A). Positive velocity represents upward motion. The vertical dotted lines show a conduction front (phase I), an evaporation front (phase II), or a reverse shock front (phase III). At these fronts, we divide the line emission into directly heated (I_heat), evaporated (I_evp), and accumulated (I_acm) plasma components. The emission ﹩[ n^{2}_{i}﹩ G(T_i)l_i] is in ergs cm⁻² s⁻¹. Note the various vertical scales among four phases.