I would like to define `non-line-termination-character = <any character other than %x000D / %x000A>` in `lexer.mll`. I have tried `let non_line_termination_character = [^('\x0D' '\x0A')]`, but it gave me a syntax error. 

I think `let non_line_termination_character = [^'\x0D'] intersect [^'\x0A']` would work, but I don't know how to express `intersect`.

Could anyone help?

PS: The rule is at `12.2.4 Regular expressions` of : <http://caml.inria.fr/pub/docs/manual-ocaml/manual026.html>