Relative synonymy
Properties

¥SynR(A, B, C) = SynR(B, A, C)

¥SynR(A, A, C) = DA(A C, A C) = 0
¥SynR(A, B, 0) = DA(A, B
¥SynR(A, 0, C) =  p/2

¥DA(charbon,nuit) = 0.9
¥SynR(charbon, nuit, couleur) = 0.4
¥SynR(charbon, nuit, noir) = 0.35