A probable beginner's mistake

[emm . charpentier]

I'd have sworn that org could evaluate inline "throwaway" code. But I seem to 
be mistaken.

The following :
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#+options: toc:nil author:nil

For the life of me, I can't explain this:

#+name: foo
#+begin_src emacs-lisp :exports code :var x=3
  (+ 2 x)
#+end_src

Inline call to a predefined function : call_foo(x=4). Works.

Inline "throwaway" code : src_emacs-lisp((+ 2 3)). Does *not* work.

What the...

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exports to (UTF8 buffer)

================================================================
For the life of me, I can't explain this:

┌────
│ (+ 2 x)
└────

Inline call to a predefined function : `6'. Works.

Inline "throwaway" code : src_emacs-lisp((+ 2 3)). Does *not* work.

What the…

================================================================

Could some kind soul explain the direction and magnitude of my mistake ?

Sincerely,

--
Emmanuel Charpentier