Syntax for references

[Jose Emilio Labra Gayo]

A possible syntax for references could be something like:

<S> {
 :P735 String 
          {| :P145 Quantity |}  # Qualifier
          References ( {| :P248 . ; :P227 . ; :P813 Time |} + ) # References
}

Notice that while qualifiers are a list of property/values, references are a list of nodes which are themselves a list of property/values. With this syntax, we can embed between parenthesis the declaration of the list of nodes.