??!! replacing ? :

I know this is completely OT in the context of this thread, but I've not been in p6l for a long time and I'm trying my hand here. Now, I've sometimes felt the need to distinguish in a single statement between "TRUE", "FALSE" and "UNDEFINED". To this effect in Perl 5 I've had to use nested ?:'s or other short circuiting operators, with an overall "too much effort" back taste. I was wondering if by any chance Perl 6 could incorporate unambiguously in ??!! an optional additional !! so that the fourth argument is returned in case the condition turns out to be undefined.