I'm following a Coursera course that uses ML. I have SML up and running on
Emacs 26.1/orgmode 9.1.14. So in an orgmode buffer I have

#+begin_src sml
val u = 1;
val v = 2;
val w = u + v;
#+end_src

and C-c C-c produces

#+RESULTS[8b5...]:
: val v = 2 : int

while the REPL (*sml*) produces

- val u = 1;
val v = 2;
val w = u + v;
; "stdIn";
val u = 1 : int
- val v = 2 : int
- val w = 3 : int
- val it = "stdIn" : string

So the RESULTS block in the orgmode buffer is not giving the full results
as does the REPL. More bizarre, I can do something later, e.g.,

#+begin_src sml
fun area_c (r) = Math.pi * r * r;
#+end_src

and the RESULTS simply replaces the RESULTS above, again only including
some of the REPL's response. I'm saying it doesn't do the normal thing of
giving a new RESULTS below the code block, rather just replaces the
previous RESULTS block's contents with incomplete information. I can add
many code blocks -- and I only ever get that lone RESULTS block
overwritten. What am I missing?

LB