It is good practice to start by identifying all of the β-redexes in the given λ expression.

Recall that the applicative-order reduction strategy first reduces the leftmost innermost β-redex, while the normal-order reduction strategy first reduces the leftmost outermost β-redex.

By leftmost innermost β-redex, we mean the first (going from left to right) among all of the innermost β-redexes.

By leftmost outermost β-redex, we mean the first (going from left to right) among all of the outermost β-redexes.