Hi, I am trying to evaluate a number of N[i,j] variables and part of the process of finding them includes "Int" and afterwards "evalf". In case I calculate them manually as in (functions, variables and constants previously defined): G11 := diff(psi2, a[1], a[1]); dpsi2 := diff(psir2, a[1], a[1])+diff(psiz2, a[1], a[1]); Izr := -E*(Int(u*G11, [z = -infinity .. infinity, r = 0 .. infinity]))+Int(u*((j*g0+j^2/r^2+(1/4)*g0^2*r^2-2/rho)*G11+dpsi2), [z = -infinity .. infinity, r = 0 .. infinity]): Izr2 := evalf(Izr); N[1,1] := (a[1]*a[1])*Izr2; I obtain neat results for Izr2 and N[1,1] (i.e. the integration is done and results in a number).