On ambivalent associations

["Sedukhin, Igor S" <Igor.Sedukhin@ca.com>]

Title: On ambivalent associations

We had this discussion today about relationships/associations being directional or not. I'm still trying to understand the reasoning behind this. One may equivalently say

#1 A and B are friends

#2 A is a friend of B and B is a friend of A

I don't understand why #1 is so important.

Handling/modeling #1 gets very intricate when there are more than two participants. "A and B and C are friends". Saying that this has to be represented as "A and B are friends" + "A and C are friends" + "B and C are friends" breaks the pattern here. This will be hard to compute.

At the same time saying that "A is a friend of B" + "A is a friend of C" + "B is a friend of A" + "B is a friend of C" + "C is a friend of A" + "C is a friend of B" does not break the pattern that was already itroduced. This is easy to compute.

The difference is 2x. That is not a significant difference.

-- Igor Sedukhin .. (igor.sedukhin@ca.com)
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