# OrLink

The **OrLink** asserts a boolean-logic disjunction of propositions. OrLink can operate over predicates or concepts, but not between concepts and predicates.

To specify a menu of choices, use the ChoiceLink instead. A choice of variable types can be specified with the TypeChoice link.

## PLN Semantics

In PLN the OrLink semantics corresponds to a fuzzy set union (accounting for confidence).

OrLink <TV> A B

with

**Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://api.formulasearchengine.com/v1/":): {\displaystyle TV.s = \frac{\sum_x f_\vee(A(x).s, B(x).s) \times x.s}{\sum_x x.s}}**

where **Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://api.formulasearchengine.com/v1/":): {\displaystyle f_\vee}**
denotes the function associated to the fuzzy connector **Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://api.formulasearchengine.com/v1/":): {\displaystyle \vee}**
, usually **Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://api.formulasearchengine.com/v1/":): {\displaystyle \max}**
.

## Example

Initially the OrLink is defined over concepts, but is overloaded to predicates as well, in that case the union is applied over the corresponding satisfying sets.

For instance one may express the OrLink between predicates like

OrLink <TV> PredicateNode "hard_working" PredicateNode "fortunate"

or concepts

OrLink <TV> ConceptNode "hard_worker" ConceptNode "fortunate_people"