t=e^x x=lnt
y=f(t)e^f(lnt)
dy/dt=f'(t)e^f(lnt)+f(t)e^f(lnt)f'(lnt)/t
dy/d(e^x)=f'(e^x)e^f(x)+f(e^x)e^f(x)f'(x)/e^x
dy=f'(e^x)e^f(x)+f(e^x)e^f(x)f'(x)/e^x d(e^x)