Maths question

Texta · Post by **Texta** » 14 Aug 2006 20:39

2. Prove that for any finite set S, P(S) is a complete lattice

My proof feels a little dodgy so if someone would like to compare that'd be awesome to the max.

wolfpac444 · Post by **wolfpac444** » 14 Aug 2006 22:15

It should be straightforward. What do you have as the partial order relation, infimum, and supremum?

janis · Post by **janis** » 14 Aug 2006 22:24

what exactly is P(S)?

james_dean · Post by **james_dean** » 15 Aug 2006 01:22

janis wrote:what exactly is P(S)?

The probability of 'S'. If you had to ask that I highly doubt you can answer the question... I know I can't... I don't even know what it's asking.

wolfpac444 · Post by **wolfpac444** » 15 Aug 2006 11:11

james_dean wrote:
janis wrote:what exactly is P(S)?
The probability of 'S'. If you had to ask that I highly doubt you can answer the question... I know I can't... I don't even know what it's asking.

Actually, I think it is the power set of the finite set S.

professor · Post by **professor** » 15 Aug 2006 12:13

Is this for discrete math?

Tsiangkun · Post by **Tsiangkun** » 15 Aug 2006 12:17

I find it to be pretty discrete, people that are into this type of thing usually keep it on the down low.

james_dean · Post by **james_dean** » 15 Aug 2006 18:11

wolfpac444 wrote:
james_dean wrote:
janis wrote:what exactly is P(S)?
The probability of 'S'. If you had to ask that I highly doubt you can answer the question... I know I can't... I don't even know what it's asking.
Actually, I think it is the power set of the finite set S.

I had a feeling I shouldn't have answered that question...

Texta · Post by **Texta** » 22 Aug 2006 20:06

james_dean wrote:
janis wrote:what exactly is P(S)?
The probability of 'S'. If you had to ask that I highly doubt you can answer the question... I know I can't... I don't even know what it's asking.

Ha ha. Lol. noob.

I smashed it with the sups and the infs. Thanks for the help though.

Iron Clad Ben · Post by **Iron Clad Ben** » 22 Aug 2006 21:41

OK total engineer comment here but what's the real world application to this kind of math? Or is this just purely theoretical stuff? I minored in math but it was all calculus and linear algebra, none of this discrete schnizznoz.

BTW Cameron I agree, discrete mathematics should be worked on discreetly.

wolfpac444 · Post by **wolfpac444** » 23 Aug 2006 07:55

Well, this particular problem would fall in the realm of lattice theory and boolean algebras. If you do any electrical engineering, I'm sure you've probably had to simplify circuits / switches. Using boolean algebra is one of the ways to do it.

If you check out http://en.wikipedia.org/wiki/Boolean_algebra , the picture they have there is a complete lattice of the power set of {1,2,3}.

Iron Clad Ben · Post by **Iron Clad Ben** » 23 Aug 2006 09:05

Yeah I did mechanical. This stuff is all ancient greek to me.

Texta · Post by **Texta** » 23 Aug 2006 20:29

Fundamentally it's how all computers work.

Though I just do it because it's fun. <_<

janis · Post by **janis** » 02 Sep 2006 02:42

I'd love it if you could post your proof for all us engineering mathematics noobs