Re: The naive test for equality

"Marshall Spight" <marshall.spight_at_gmail.com> wrote in message news:1122960074.359597.49310_at_g14g2000cwa.googlegroups.com...
> I have to say I just don't understand why equality produces
> so much ink. It's not that complicated a concept: two
> values are equal if they are the same value.
>

The reason it produces so much ink is that we never actually compare two objects directly. What we compare are two representations of objects to see if the represent the same object.

And the issues of homonyms and synonyms in representation schemes is worth quite a bit of ink.

I was thankful when DBMS_plumber informed us that these issues have been fully treated in the literature. It would have been very disconcerting to find out the opposite. And certainly urge anyone who proposes to build a DBMS to bone up on the literature first. The time invested will yield a good return.

Further, the plumber is very right to state that, once a bitwise representation scheme has been proven satisfactory with regard to identity, the next issue is order. But that's not where I'm going with this. I proposed the "naive test" as a straw man, and I hope no one thinks I was setting some kind of trap.

I'm still not done with identity. In particular, I'm not done with synonyms.

The synonyms "humid" and "moist" get into semantic issues that are way beyond where I want to go right now.

Instead, I'm going to suggest anagrams: a valid word with the same letters, but possibly permuted.

Thus if I ask for anagrams of: "post", I get "stop", "pots", etc. If I extend the definition of anagrams just slightly, and define that every word is an anagram of itself, now the relationship is reflexive. It's clearly symmetric and transitive, so it's a flavor of "equality".

But it's a flavor of equality where the combinatorics get quickly out of hand.

And that's what interests me in this discussion. Received on Tue Aug 02 2005 - 14:37:19 CEST