Qmd1[x_, rho_] := Module[{n,t}, If [rho < .3, If [x < 9 + 15 Log[10, .3 / rho], Qmd1series[x, rho], Qmd1asymp[x, rho] ], If [x > 8, Qmd1asymp[x, rho], Qmd1poly[x, rho] ] ] ](* needs also the definition of the functions Qmd1asymp, Qmd1poly and Qmd1series *)