Subjective synonymy
When |C| ¨ ´ then SynS(A, B, C) ¨ 0
SynS(A, B, 0) =
D(-B, -A) = D(A, B)
SynS(A, A, C) = D(C-A, C-A) = 0
SynS(A, B, B) = SynS(A, B,
A) = 0
¥SynS(tit, swallow, animal) 
=
0.3
=
0.3¥SynS(tit, swallow, bird) =
0.4
=
0.4¥SynS(tit, swallow, passerine) =
1
=
1