Re: Question on modular types

[jvl@ocsystems.com (Joel VanLaven)]

Robert Dewar (dewar@merv.cs.nyu.edu) wrote:
: Tuck said (answering my query about unary minus on modular types)

: "Two places: 3.5.4(19) gives the general rule that anytime the result
: of a predefined operator of a modular type is outside the base range of
: the type, the result is reduced modulo the modulus of the type.
: The second is in a note, 4.5.4(3)."


: Ah, yes, silly me, expecting to find the semantics of unary minus in
: the section on operator semantics (or at least in the chapter on
: expression semantics) :-)

: Yes, I saw the note, but the question was where that note came from,
: especially since 4.5.4(1) says that "-" on modular types has its
: conventional meaning (which I can only take as the mathematical
: meaning), and hence contradicts 3.5.4(19).

  It seems to me that the conventional mathematical meaning of "-" for
a modular type IS the definition given in the note.  I am sure that what
is the conventional, mathematical meaning is if not the modular
definition then at least debatable, and if debatable then the note is
intended to show which side of the debate the RM/RM writers came out on.
Perhaps it could be worded better so as not to cause confusion.
-- 
-- Joel VanLaven