🚀 go-pugleaf

> In article <graham.714740051@galois> graham@maths.su.oz.au (Graham Matthews) writes:
> >Why not take this the whole hog and treat your object heirarchy as an
> >ordered set (which it is in the single inheritance model - not sure
> >about multiple inheritance) and allow the programmer to write a type
> >spec like
> >
> >	function f( <= type_A, > type_B )
> 
> This is meaningful even with multiple inheritance, because the the class
> hierarchy is a DAG, so there's a partial order, which is all you need.

I think it's like this: There's a partial order if < means subclass,
but not if it means "more specific".  (You might have A < B in the cpl
of one class and B < A in the cpl of another.)  In single inheritance,
there's a partial order in both cases.  But I'm not sure what Graham
meant < to be.