legitimate closure?

This closure works on clisp on cygwin+windows:
cl-user> (let ((list (list 1 2 3 4 5))
(item 4))
(delete item list :test #'(lambda (unused b) (= item b))))
(1 2 3 5)

I used closure for lambda to get "item" from delete's first argument

The straightforward version is
cl-user> (let ((list (list 1 2 3 4 5))
(item 4))
(delete item list :test #'(lambda (a b) (= a b))))

I'm not sure why would this ever be useful, but I was surprised that
lambda captured it.

Mirko
.