not quite understanding input methods

["Perry E. Metzger" <perry@piermont.com>]

So I've built a small input method to test out my understanding, and 
I've hit a bit of a wall.

I would like to prefix my translations with a special character. I've 
mapped my caps lock key to send F19 (I don't use the caps lock key ever 
and using it as a compose key seems reasonable) and I've set Emacs to 
insert a special character for me when I hit that key, like so:

(global-set-key (kbd "<f19>")
                 (lambda (n)
                   (interactive "p")
                   (self-insert-command n ?⎄)))

(That special character happens to be the unicode "COMPOSE SYMBOL", 
which seemed intuitively appropriate.)

I've also created a small input method, and which has the following rules:

(quail-define-rules
  ("⎄gl" ?λ)
  ("⎄gL" ?Λ)
  ("⎄iA" ?∀)
  ("⎄iE" ?∃)
   ("xx" ?Π)
)

Now, if I hit "xx", Π is inserted as expected, but if I hit "<F19> g l", 
the buffer shows me "⎄gl" and not "λ" as I would expect.

My guess is that something in the belly of Quail is reading events and 
not the characters in the buffer, but as there's no documentation I'm 
not really clear on what is going on.


Perry