anchor.diff:    ?person v:age ?age . }""")
   ----
   
  -[[pattern-matching]]
   ==== Pattern Matching
   
   Select only those persons who created a project.
  
positive.code: = Gremlin Compilers
  
  There are many languages built to query data. SQL is typically used to query relational data. There is SPARQL for RDF
  data. Cypher is used to do pattern matching in graph data. The list could go on. compilers convert languages like
  these to Gremlin so that it becomes possible to use them in any context that Gremlin is used. In other words, a
  Gremlin Cranspiler enables a particular query language to work on any TinkerPop-enabled graph system.
  
  [[sparql-gremlin]]
  == SPARQL-Gremlin
  
negative.code: } ORDER BY (?age))
  ----
  
  ==== Group By
  
  Select all vertices with the label `person` and group them by their age.
  