Thermodynamic pressure, P, for isospin-symmetric matter (left panel) and under the NS conditions of β-equilibrium and charge neutrality (right panel), as functions of the net-baryon number density, ρ_B, in units of the saturation density, ρ₀ = 0.16 fm⁻³ for m₀ = 700 MeV, αb₀ = 370 MeV and different values of the parameter χ (see text for details). Left panel: the flow constraint (Danielewicz et al. 2002) is shown as the gray shaded region. In both panels, the inset plots show pressure for χ = 0 and different values of the parameter α, in the vicinity of the constraints obtained by Danielewicz et al. (2002) (left panel) and Hebeler et al. (2013) (right panel). We note that the inset figure in the right panel shows pressure as a function of energy density. In both panels, the first-order phase transitions are seen as plateaux of constant pressure.