anchor.diff:  ----
   SELECT LOWER(SPLIT(" ", line)) AS word FROM receiver
   ----
  +
  +In that case the function +lower+ would of course be applied to each of +split+
  +results.
   
   WARNING: Notice that function names are case insensitive but keep in mind that
   field names are _not_!
  
positive.code: COMMIT AND FLUSH WHEN out.count <> previous.count
  ----
  
  ...then we would have a succession of +$word, 2+ tuples, emitted each other
  time a word is encountered, that would not be very useful.
  
  [NOTE]
  Notice there is an +out+ special tuple in addition to the +previous+ special
  
negative.code: 
  It will return from 1 (if the separator is not found) to many results.
  
  When a function outputs several results then as many tuple will be output by
  the node. That is, for one input there will be N outputs. When the SELECT
  statement uses several such functions returning multiple results then the
  Cartesian product of all those results is output.
  
  So for instance the output tuples of +split(" ", "foo bar"), 42+ would be:
  
    "foo", 42
    "bar", 42
  
  and the output tuples of +split(" ", "foo bar"), 42, split(" ", "baz bam")+
  would be:
  
    "foo", 42, "baz"
    "foo", 42, "bam"
    "bar", 42, "baz"
    "bar", 42, "bam"
  
  In our case we just want to split incoming field +line+ by spaces:
  
  