> CAML allows me to define the following prefix identifier:
> 
> let prefix !~ = ....
> 
> Objective CAML documentation says it allows ! (and ? and ~) as prefix
> operators, too, but I get "Characters 11-13: Syntax error" when I try.
> How do I use prefix characters in OCAML?
> 
> Trent
> 
> (Apologies for no French.)

You should enclose your infix operator into parens, instead of using
the prefix keyword:

#  let (!~) x = x + 1;;
val !~ : int -> int = <fun>

Pierre Weis

INRIA, Projet Cristal, Pierre.Weis@inria.fr, http://pauillac.inria.fr/~weis/