Applicative order is said to be leftmost, innermost. But I often here, it means "first evaluate the arguments". Sometimes I'm confused to what actually applies in what case. Here's an example:
$$(λxyz. (λwvu. M) N O P) ((λz.z)f) O P$$
What does leftmost, innermost mean in this case? Is:
$$(λxyz. (λwvu. M) N O P) f O P$$ the first step, or:
$$(λxyz. M[w=N,v=O,u=P]) ((λz.z)f) O P$$ ?