Even passing over that, it&#x27;s only a closure if it keeps a lexical environment.<p>(lambda (x) (+ x 1)) doesn&#x27;t close over anything, so it&#x27;s not a closure, nor does it evaluate to one. For that matter, (let ((x 0)) (lambda (x) (+ x 1))) isn&#x27;t <i>really</i> a closure in any sense because the environment can be inlined out.