out tt;
off nat;


J:=p**2 - 4*e**ro;

df(J,tt) + df(J,ro)*p + df(J,p)*2*e**ro;

D:= - tt/2 + log( (p-sqrt(J))/(p+sqrt(J)) )/(2*sqrt(J));

df(D,tt) + df(D,ro)*p + df(D,p)*2*e**ro;
%-----------------------------------------

D:= - tt/2 + atanh(-p/sqrt(J)) / (sqrt(J));

df(D,tt) + df(D,ro)*p + df(D,p)*2*e**ro;


shut tt;
bye;
end;