anchor.diff:  - A case expression has multiple operands -- a value to test, for every case a test value/predicate and a result value, and a default value of the 'else' case
   
   Some operands expect non-values, typically identifiers (variable names, function names, property keys, etc.).
  -Such _non-value operands_ do not allow nesting of expressions because expression only resulting in values.
  +Such _non-value operands_ do not allow nesting of expressions because expression only result in values.
  +
   However, most operands expect values of some types.
   Such _value operands_ allow nesting of all expressions that result in a values of the expected type.
  -The nested expressions form a tree and are typically evaluated bottom-up, i.e. all expressions are evaluated that provide an operand before the expression is evaluated that takes these operands.
  +The nested expressions form an _operator tree_ and which typically evaluated bottom-up, i.e. all expressions that provide an operand are evaluated before the expression is evaluated that take this operands.
   (Higher-order expression, e.g. list comprehensions, have operands which are exceptions to this bottom-up evaluation.)
  -In other words, the nesting tree encodes the evaluation order.
  -For instance, the following tree
  +In other words, the operator tree encodes the evaluation order.
  +For instance, the following operator tree
   ----
       *
      / \
  
positive.code: ----
  (3+(2*4))
  ----
  and, hence, results in 11 (rather than 20).
  
  This CIP states the precedence rules of openCypher.
  
  
negative.code: 
  The expression sub-languages of openCypher (and most other query and programming languages) allow very liberal composition of different elementary expressions into complex expressions through nesting.
  Elementary expression the kinds of expressions the expression sub-languages provides and which for the building blocks of the sub-languages.
  
  Some elementary expressions have zero operands, e.g. literals.
  Most elementary expressions have one or more operands.
  For instance,
  