anchor.diff:  */
   
   location_header:
  -  LOCATION_HEADER
  -;
  -
  -ATTRIB_NAME: ('a'..'z' | 'A'..'Z')('a'..'z' | 'A'..'Z')+ ('.') TOKEN;
  +  LOCATION_HEADER location_paths
  +;
  +location_paths:
  +  location_path (',' location_path)*
  +;
  +location_path:
  +  PATH
  +;
  +
  +ATTRIB_NAME: ('a'..'z' | 'A'..'Z')('a'..'z' | 'A'..'Z' | DIGIT)+ ('.') TOKEN;
   PATH: ('/' TOKEN) ('/' TOKEN)*;
   CLASS: ('kind'|'mixin'|'action');
   URI: ('http://' | 'https://') TOKEN;
   TOKEN: ('a'..'z' | 'A'..'Z') ('a'..'z' | 'A'..'Z')*;
  -DIGIT: '0'..'9'*;
  +DIGIT: '0'..'9'+;
   WS: (' ' | '\t'){$channel = HIDDEN};
positive.code:   attribute-name   = attr-component *( "." attr-component )
    attr-component   = LOALPHA *( LOALPHA | DIGIT | "-" | "_" )
  
  Example: 
    X-OCCI-Attribute: occi.compute.architechture="x86_64"
    X-OCCI-Attribute: occi.compute.architechture="x86_64", occi.compute.cores=2
  */
  
  attribute_header:
    ATTR_HEADER
  ;
  
  
  // ---------------------------------------- 
  // ------ X-OCCI-Location attribute -------
  // ---------------------------------------- 
  /*
  
  ABNF representation of X-OCCI-Location from the http rendering specification
  
negative.code:   OPEN_PATH link_path_val CLOSE_PATH
  ;
  link_path_val:
    PATH
  ;
  
  self:
  