the star formation history (SFH) of dynamical models into the chemical code of @Portinari98. The closed-box approximation is adopted. The total baryonic mass of the chemical models is the same as in the dynamical ones. Equally for the initial mass function of the stars composing each star particle: @Kroupa98 in our case. In Fig. \[BIG\_SF\] we show the results obtained by inserting the SFH of Model A into a classical chemical model with total baryonic mass $M_B$ equal to $1.6 \cdot 10^{11} M_{\odot}$. The top panels display the adopted SFH (left) and the gas metallicity of the chemical model, respectively. The bottom left panel shows the temporal variation of the star mass $M_{star}$ and gas mass $M_{gas}$, whereas the bottom right panel shows the ratios $M_{star}/M_B$ and $M_{gas}/M_B$ for both the dynamical (thin lines) and chemical model (thick lines). The agreement is very good thus confirming the internal consistency between the descriptions of the same object. We also show the amount of gas at $13$ Gyr contained in the whole galaxy for both the dynamical (heavy dots) and the classical chemical models (open circles) and the amount of gas contained inside $R_{gal}$ (open squares). Indeed there is little gas left 