A type of Link used in OpenCog to define extensional implication.

${\displaystyle \operatorname {sim} (A,B)={\frac {P(A\wedge B)}{P(A\vee B)}}}$
where ${\displaystyle \wedge }$ denotes the fuzzy intersection. The TV of the similarity of A and B can also be seen as the TV of concept ${\displaystyle A\wedge B}$ in the context ${\displaystyle A\vee B}$ as explained in this thread [1]