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To: caml-list@pauillac.inria.fr
Cc: John.Harrison@cl.cam.ac.uk
Subject: Bug in equality testing?
Date: Sun, 20 Mar 94 15:24:23 +0000
From: John Harrison <John.Harrison@cl.cam.ac.uk>
Message-Id: <"swan.cl.cam.:202150:940320152434"@cl.cam.ac.uk>
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Hi,

I've come across the following, which unless I am being stupid
looks like a bug. The program below produces (in 0.6):

  true; true; false

John.

P.S. Thanks for the interesting replies on hash-consing. I'm afraid
I am likely to be pestering you with more questions about CAML soon.
It's a great system!

**********************************************
type Example = Var of string            
             | App of string *  Example list;;

let DEST = 
  fun (App p) -> p 
    | (Var _) -> failwith "DEST";;
          
let a = DEST(App("X",([]: Example list)));;
let b = ("X",([]: Example list));;
 
fst(a) = fst(b);;
snd(a) = snd(b);;
a = b;; 
**********************************************