with(gfun); with(NumGfun);
a := 1/3;
tests := 10;
interface(quiet=true);
deq := diffeqtohomdiffeq(holexprtodiffeq(arctan(z),y(z)),y(z));
seq(time(ac_eval(deq,y(z),[0,a],100*2^j)),j=0..tests);
gc();
seq(time(evalf(arctan(a),100*2^j)),j=0..tests);
