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- Subject: Re: [ANN] Lua 5.3.2 (rc1) now available
- From: Roberto Ierusalimschy <roberto@...>
- Date: Thu, 19 Nov 2015 09:08:00 -0200
> > Shouldn't that be a (strict) *total* order (i.e. all elements may
> > be compared to each other)?
>
> The total order need not be strict (i.e. it is perfectly OK for
> comp(a,b) and comp(b,a) to be both false).
>
> The specification in the manual requires that :
>
> 1. comp(a,b) and comp(b,c) implies comp(a,c)
> 2. comp(a,b) implies not comp(b,a)
A "strict order" means not comp(a,a) (that is, it is irreflexive). Rule
2 above implies strictness (comp(a,a) => not camp(a,a)). Rules 1 and 2
above define a (strict) partial oder. And that is what 'sort' needs.
-- Roberto