Language tagged annotations seem to fail

[labra]

The following example raises an error but is correct. I think the problem is that the value of label is a language tagged literal.

PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX :       <http://example.org/>
PREFIX xsd:  <http://www.w3.org/2001/XMLSchema#>

:User {
  :name          xsd:string // rdfs:label "nombre"@es ;
}