Re: Transitive Closure

On Tue, 18 May 2004 10:54:36 -0700, "Mikito Harakiri" <mikharakiri_at_iahu.com> wrote:

>Boolean function on what space?

On the space of the other operand: the relation. What's the problem?

>> > Cartesian Power (as product is, unfortunately, binary
>> > operator)
>>
>> It could be defined as an n-ary operation like: join, semijoin, union,
>> intersection, etc.
>>
>> *(a,b,c) = *(a,c,b) = *(b,a,c) = *(b,c,a) = *(c,a,b) = *(c,b,a)
>
>What '*', and letters mean there?

'*' could be cartesian product and letters relations.

>
>> >, transitive closure, and, perhaps, negation. In this tiny 4
>> > element universe we define one binary operation: composition of unary
>> > relational operators.
>>
>> Which composition?
>
>http://mathworld.wolfram.com/Composition.html

It says that composition is associative, not commutative and that's what I am trying to say all the time.

Commutativity is about the order of the operands of an n-ary operation and not about the order of the operations.

http://mathworld.wolfram.com/Commutative.html

Regards
  Alfredo Received on Tue May 18 2004 - 23:41:01 CEST