Question: showstat() and finding the next call when looking at source code of Maple?

One of the things I like about Maple, is that I am able to look at most of the source code, and learn from it. But since I am newbie in Maple, sometimes I find it hard to know which next call I need to showstat() in order to see what happens next and follow the code.

Sometimes I do not know how to find the proc() being called in the listing shown by showstat().

For an example, I wanted to see how Maple implements AiryAi(x).

So I did  showstat(`AiryAi`) and I see the listing of AiryAi. The top level of the function. But then I see it calling, which must be some other level of `AiryAi` function? For example, at line 16, it says

     res := ('AiryAi')(x)

Since I am looking at AiryAi itself, this must be either recursive call or calling other internal AiryAi?

But if it recursive, then I do not see where the actual implementation is? I wanted to see if it uses the integral form of AiryAi or series form (not likely, uses GAMMA). I see the same recursive call in many places, such as line 35 and line 37 and othere places.

But looking at all the 42 lines, I do not see where the actual calculation of AiryAi(x) is done. Did I miss it?

There is a lot of error checking and looking at special cases and such. But how does one know from looking at this listing, which other function they need to showstat() in order to see the actual implementation? There must be more to it than those 42 lines?

This is on Maple 2016.2