zuse: +tab in ordered-map is more succinct and no longer nips
=. f $(a l.a)
?: =(d.f c) f
=. f [+(d.f) [n.a e.f]]
- ?: =(d.f c) f
- $(a r.a)
+ ?:(=(d.f c) f $(a r.a))
::
++ del-span
|= [a=(tree item) b=(unit key)]
?~ a a
?~ b a
?: =(key.n.a u.b)
- (nip a(l ~))
+ a(l r.a)
?: (compare key.n.a u.b)
- $(a (nip a(l ~)))
+ $(a a(l r.a))
a(l $(a l.a))
--
:: +tap: convert to list, smallest to largest
