fixes a bug in +nap:to affecting three-item queues
::
++ nap :: removes head
?> ?=(^ a)
- ?: =(~ l.a) r.a
- =+ b=get(a l.a)
- bal(a ^+(a [p.b q.b r.a]))
+ ?~ a ~
+ =+ b=get
+ ?~ q.b ~
+ bal(a ^+(a [n=n.q.b l=l.q.b r=r.q.b]))
::
++ put :: insert new tail
|* b/*
