(any? f it)
  f: a callable
  it: an iterable
  returns a bool
F

Lazily tests whether any of an iterator's items match a predicate.

Repeatedly produces items from the base iterator and passes them to (f item). If that call returns something other than #n or #f, the function exits early and returns #t, and the iterator is not completely consumed. Otherwise, the function returns #f.

nth-back
all?