Fixes errors and reflows

Author: JJ

doc/Type/Mix.pod6

@@ -62,7 +62,8 @@ values become the associated numeric weights:
 
 =head1 Operators
 
-C<Mix>es can use all kind of set operators returning either C<Bool> or other C<Mix>es:
+C<Mix>es can use all kind of set operators returning either C<Bool> or
+other C<Mix>es:
 
 =begin code
 my $this-mix = (sugar => ⅓, spice => ¼, all-things-nice => ¾);
@@ -74,7 +75,7 @@ say $that-mix (+) $this-mix;     # OUTPUT: «Bag(spice(2), sugar)␤»
 =end code
 
 With their equivalent Unicode operators:
-=begin code :preamble<my ($this-mix, $that-mix);
+=begin code :preamble<my ($this-mix, $that-mix);>
 say $that-mix ⊂ $this-mix;     # OUTPUT: «True␤»
 say $that-mix ⊖ $this-mix;     # OUTPUT: «set(all-things-nice)␤»
 say $that-mix ⊎ $this-mix;     # OUTPUT: «Bag(spice(2), sugar)␤»