[m-dev.] assertions (was: Assocative predicates)

[Andrew Bromage]

G'day all.

Fergus Henderson wrote:

> One way of working around this would be to use a "not_reached" mode
> 
> 	% na stands for "not applicable"
> 	:- mode na == not_reached -> not_reached.
> 
> 	:- mode associative_function(na) is erroneous.

UGH!  NO NO NO!  We are NOT letting programmers use not_reached insts!
They're bad enough to deal with when the compiler generates them, let
alone letting the user get a handle on them.

Did I put that strongly enough?

Cheers,
Andrew Bromage