anchor.diff:  <   <=   ==   !=   >=   >
   ----
   
  +.*Definitions*
  +[%collapsible]
  +====
  +`<` (less than)::
  +Returns `true` if the value to the left of the operator is less than the value
  +to the right. Otherwise returns `false`.
  +
  +`<=` (less than or equal) ::
  +Returns `true` if the value to the left of the operator is less than or equal to
  +the value to the right. Otherwise returns `false`.
  +
  +`==` (equal)::
  +Returns `true` if the values to the left and right of the operator are equal.
  +Otherwise returns `false`.
  +
  +`!=` (not equal)::
  +Returns `true` if the values to the left and right of the operator are not
  +equal. Otherwise returns `false`.
  +
  +`>=` (greater than or equal) ::
  +Returns `true` if the value to the left of the operator is greater than or equal
  +to the value to the right. Otherwise returns `false`.
  +
  +`>` (greater than)::
  +Returns `true` if the value to the left of the operator is greater than the
  +value to the right. Otherwise returns `false`.
  +====
  +
   You cannot use comparison operators to compare a variable, such as a field
   value, to another variable, even if those variables are modified using a
   <<eql-functions,function>>.
  
positive.code: 
  To search `text` fields, consider using a <<eql-search-filter-query-dsl,query
  DSL filter>> that contains a <<query-dsl-match-query,`match`>> query.
  ====
  
  .*Definitions*
  [%collapsible]
  ====
  `<` (less than)::
  Returns `true` if the value to the left of the operator is less than the value
  to the right. Otherwise returns `false`.
  
  `<=` (less than or equal) ::
  Returns `true` if the value to the left of the operator is less than or equal to
  the value to the right. Otherwise returns `false`.
  
  `==` (equal)::
  Returns `true` if the values to the left and right of the operator are equal.
  Otherwise returns `false`.
  
  `!=` (not equal)::
  Returns `true` if the values to the left and right of the operator are not
  equal. Otherwise returns `false`.
  
  `>=` (greater than or equal) ::
  Returns `true` if the value to the left of the operator is greater than or equal
  to the value to the right. Otherwise returns `false`.
  
  `>` (greater than)::
  Returns `true` if the value to the left of the operator is greater than the
  value to the right. Otherwise returns `false`.
  ====
  
  [discrete]
  
negative.code: 
  experimental::[]
  
  IMPORTANT: {es} supports a subset of {eql-ref}/index.html[EQL syntax]. See
  <<eql-syntax-limitations>>.
  
  [discrete]
  [[eql-basic-syntax]]
  