<<>> question

[ToddAndMargo]

Hi All,

I am writing up a keeper note on <<>> and such.  This example
puzzles me.  Why the space?

Example of <<>> (double quote and allow insertion of variables into 
strings):


   $ perl6 -e 'my $x="abc"; my $y=<<xyz{$x}def>>; say "\$x=$x \$y=$y";'
   $x=abc $y=xyz abc def



Many thanks,
-T