I've noticed another equivalence
SimilarityLink <TV>
A
B
==
ContextLink <TV>
A OR B
A AND B
1) by def
$$(SimilarityLink A B).TV = \frac{(A \cap B).TV}{(A \cup B).TV}$$
2)
ContextLink <TV>
A OR B
A AND B
==
SubSet <TV>
A OR B
A AND B
let be
f_A the function corresponding to the fuzzy set of A,
f_B the function of B.
f_c the function of (A OR B) with obviously f_c = max(f_A,f_B),
f_d the function of (A AND B) with obviously f_d = min(f_A,f_B),
$$TV = \frac{\sum_x x.TV \times min(f_c(x),f_d(x))} {\sum_x x.TV
\times f_c(x)}$$
$$TV = \frac{\sum_x x.TV \times
min(max(f_A(x),f_B(x)),min(f_A(x),f_B(x)))} {\sum_x x.TV \times
max(f_A(x),f_B(x))}$$
$$TV = \frac{\sum_x x.TV \times min(f_A(x),f_B(x))} {\sum_x x.TV
\times max(f_A(x),f_B(x))}$$
Although it's perhaps not a requirement of the PLN theory (or perhaps
it is?) I think it's fair to assume that
$$(A \cap B).TV = \sum_x x.TV \times min(f_A(x),f_B(x))$$
and
$$(A \cup B).TV = \sum_x x.TV \times max(f_A(x),f_B(x))$$
think of the TV of some concept C as the average intensity at which
pattern C occurs...
So to sum up the similarity between A and B can be seen as the TV of
(A AND B) in the context of (A OR B). Kinda obvious but I didn't see
it before!
Nil
Nil
--
You received this message because you are subscribed to the Google Groups "opencog" group.
To post to this group, send email to ope...@googlegroups.com.
To unsubscribe from this group, send email to opencog+u...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/opencog?hl=en.
oh well, of course it's a PLN "requirement", fairly obvious (albeit a
missing normalizing factor) using
A <TV>
==
Subset <TV>
Universe
A
...
Nil