From: Marco (mrcekets_at_[hidden])
Date: 2007-04-22 12:28:54
On Sun, 22 Apr 2007 12:31:44 +0200, Larry Evans
> Actually, I think and_ and or_ are the meet and join of
> a lattice:
> is the top element
> is the bottom element
> However, I'm not sure about this since I don't know
> if the and_ and or_ operations are associative
> and commutative, which is one of the requirements
> for a lattic (I think).
Well, the last word is up to the author's library, however I'd be
surprised if the following relations were not valid:
or_< T1, or_<T2, T3> > == or_< T1, T2, T3 > == or_< or_<T1, T2,>, T3 >
and_< T1, and_<T2, T3> > == and_< T1, T2, T3 > == and_< and_<T1, T2,>, T3 >
or_< T, U > == or_< U, T >
and_< T, U > == and_< U, T >
or_< T, and_<T, U> > == T
and_< T, or_<T, U> > == T
obviously where "==" means logical equivalence not C++ data type equality.
Distibutivity shuold hold, too.
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