Question about input to relational network

[fernande2000]

I do not understand well how you pair the objects. My question is if each pair of objects is feed as input once or twice. If it is fed once then how do you choose the order? to be independent of the order each pair should be fed twice, right? Otherwise there is some break of symmetry in the input pair. I could not understand this from the original article, and the code is still obscure to me to understand this. thanks!
UPDATE: I think I got it know, you input all pairs twice (in different order each time), and also each object with itself, thus n^2 instead of n(n-1)/2, Is this correct?