anchor.diff:  
   [discrete]
   [[eql-syntax-lookup-operators]]
  -==== Lookup operators
  +=== Lookup operators
   
   [source,eql]
   ----
  
positive.code: 
  [discrete]
  [[eql-syntax-math-operators]]
  ==== Math operators
  
  [source,eql]
  ----
  
negative.code: 
  [discrete]
  [[eql-syntax-escape-a-field-name]]
  === Escape a field name
  
  Use enclosing enclosing backticks (+++`+++) to escape field names that:
  
  