TAPL book, page 56 reads:
Under the normal order strategy, the leftmost, outermost redex is always reduced first.
I understand this as a restriction of the full beta-reduction evaluation strategy, whose reduction rules are given as follows:
$$\frac{t_1 \to t_1'}{t_1 t_2 \to t_1' t_2}$$
$$\frac{t_2 \to t_2'}{t_1 t_2 \to t_1 t_2'}$$
$$\frac{t_1 \to t_1'}{λx. t_1 \to λx. t_1'}$$
$$\frac{(λx. t_1) t_2}{[x \to t_2] t_1}$$
My question is how to transform these rules so that the normal order strategy condition holds.