Third, http://dev.perl.org/perl6/doc/design/syn/S12.html says:
You can also mixin a precomposed set of roles:
$fido does Sentry | Tricks | TailChasing | Scratch;
Should that be the following?
$fido does Sentry & Tricks & TailChasing & Scratch;
If you follow my idea of a type lattice build from roles with | as join
and & as meet operator these two mean something completely different.
The first is the join or union of the roles while the second is their
meet or intersection. The first creates a subtype of the roles the
second a supertype. But the typishness of roles is debated.