anchor.diff:  ----
   
   _Example 1B:_
  +Return all nodes with both first name and second name:
   [source, cypher]
   ----
   MATCH (actor)
  -WHERE EXISTS(actor["slogan"])
  +WHERE EXISTS(actor.firstName + actor.lastName)
   RETURN actor
   ----
  -
   
   _Example 2A:_
   
  
positive.code: 
  == Background
  
  In a way, Cypher already has existential subqueries - pattern predicates allow checking for the existence of subgraphs. This form is helpful, but not exhaustive in the forms of subqueries that users want to be able to express.
  
  == Proposal
  
  To make this feature more powerful, add a new EXISTS-function, that would exist in two forms:
   . Property existence checking
   . Subquery existence checking
  
  === Syntax
  
  
negative.code: ----
  
  === Interaction with existing features
  This replaces the pre-existing +HAS(...)+ function.
  
  == What others do
  
  This is very similar to what SQL does with its EXISTS functionality.
  
  This is also very similar in syntax to what SPARQL does with its EXISTS functionality; the rules regarding variables are identical, and the inner query also takes a subquery as input.
  
  == Benefits to this proposal
  
  The existing pattern predicate functionality is very useful, but does not cover all cases.
  Pattern predicates do not allow for introducing variables, which makes some queries - such as the one below - difficult to express succinctly:
  
  [source, cypher]
  ----
  