Isn't "transitive" the wrong word?

[Bruno Medeiros]

Janice Caron wrote:
> 
> Aha - so
> 
> (1) "const" is short for "const with respect to reachability", and
> 
> (2) "const with respect to reachability" actually means "(a is const)
> and (b is reachable from a) implies (b is const)".
> 
> So, when we say "const is transitive", what we /in fact/ mean is:
> 
> ((a is const) and (b is reachable from a) implies (b is const)) and
> ((b is const) and (c is reachable from b) implies (c is const))
> implies ((a is const) and (c is reachable from a) implies (c is
> const))
> 
> Now why didn't I see that before? It's just so blindingly obvious!
> (The sarcasm wasn't aimed at you, by the way. Thanks for explaining).
> 
> So, we're all clear, right? Everyone understands why we say "const is
> transitive", not "const is recursive"?

You say "It's just so blindingly obvious!" with sarcasm, as if it isn't 
obvious?

Well, I *do* think all of the above is indeed obvious. (or at least 
"clear"). In fact, saying "const is transitive" is clearer to me than 
saying "const is recursive".
You seem to think "transitive" is something that is said only of binary 
relationships. But another common usage is saying a given property is 
transitive, which is taken to mean that that property applies to all 
"objects" reachable from the original "object". Brad Roberts said it 
best, so I'll just quote him:

"The term 'transitive' comes from the term 'transitive closure' used in
graphs.  Data structures form a graph and so the term transitive applies
quite well."


-- 
Bruno Medeiros - MSc in CS/E student
http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#D