anchor.diff:  
   Provide the full range of syntactic additions and modifications in EBNF (https://en.wikipedia.org/wiki/Extended_Backus-Naur_Form) format, along with explanatory text.
   
  -*_Example:_* +
  -_Extend expressions to support string search operators:_
  +_An example of this is shown below:_
   
  +[source, ebnf]
  +.Extend expressions to support string search operators
   ----
   expression    = current definition of expression
                 | string-search
  
positive.code: 
  == Caveats to this proposal
  
  List any caveats here. These may include omissions, reasons for non-conformance with other features and so on.
  
  == Appendix
  
  
negative.code: 
  If applicable, include a feature comparison table, along with any useful links.
  
  To provide a well-rounded comparison, please ensure the inclusion of at least one SQL-based implementation -- such as DB2 or Postgres -- as well as SPARQL.
  If you require any assistance or pointers to the latter, please contact petra.selmer@neotechnology.com.
  
  == Benefits to this proposal
  
  