Question: Powers of a piecewise function

Hi

I was wondering how maple deals with the powers of a piecewise function. I've a piecewise function of f of thins kind

A_eff:=proc(f)
global Enn,f_a,f_b,f_c,alpha_var, Ell_lor,w_var;

piecewise(f<f_a, (f)^(-7/6), f< f_b and f >=f_a, alpha_var[1]^(-23/2)*(f/alpha_var[1])^(-2/3), f< f_c and f >= f_b, alpha_var[1]^(-7/6)*w_var*Ell_lor(f,alpha_var[2],alpha_var[3]))

end proc:

and then I must integrate A_eff^2 over a range of frequency which begins before f_a and ends at f_c

I've some suspects that there is some problem with that, because if I write the integrals one at the time ( from f_low to f_a with the square of the first component of A_eff, plus the integral from f_a to f_b, ecc) and I get a different result than if I compute the integral from f_low to f_cut ot the piecewise directly, letting to Maple the task of cutting it.

Is there some tricks?

thanks.

S.