anchor.diff:    ;
   
   PREFIXEDNAME
  -   : PNAME_LN | PNAME_NS
  -   ;
  +  : PNAME_LN | PNAME_NS
  +  ;
   
   PNAME_LN
  -   : PNAME_NS PN_LOCAL
  -   ;
  +  : PNAME_NS PN_LOCAL
  +  ;
   
   BLANK_NODE_LABEL
     : '_:' (PN_CHARS_U | [0-9]) ((PN_CHARS | '.')* PN_CHARS)?
  
positive.code:  If src/main/<subPath>/TurtleOBDA.g4 is the path to this file,
   then the source files are generated in target/generated-sources/antlr4/<subPath>
   */
  //options {
  //  superClass = AbstractTurtleOBDAParser ;
  //}
  
  @header {
  import it.unibz.inf.ontop.model.term.*;
  
negative.code: base
    : ('@base' | '@BASE') iriref
    ;
  
  triples
    : subject  predicateObjectList
  