slime/bin/tests/lexical_scope.slime.expanded

(define (make-counter) ((lambda (var) (lambda () (mutate var (+ 1 var)) var)) 0))

(define counter1 (make-counter))

(assert (= (counter1) 1))

(define counter2 (make-counter))

(assert (= (counter2) 1))

(assert (= (counter2) 2))

(assert (= (counter1) 2))

(assert (= (counter1) 3))

(assert (= (counter2) 3))