# AttractionLink

From OpenCog

AttractionLink (TODO: add description, which entails that I actually understand it).

## PLN Semantics

In

AttractionLink <TV> X Y

the TV on the AttractionLink represents the difference between and , we say that X is attracted to Y. For instance if X and Y are concepts, the strength of TV (letting aside the influence of confidence for now) will be

where TV1.s and TV2.s are defined with

SubsetLink <TV1> X Y

SubsetLink <TV2> Not X Y

and is the positive part of . Note that the resulting TV of the attraction link is not a probability (or at least not obviously so).

## Related

See PredicateFormulaLink for an example of specifying formulas in Atomese.