(define liars (lambda () (let ((betty (amb 1 2 3 4 5)) (ethel (amb 1 2 3 4 5)) (joan (amb 1 2 3 4 5)) (kitty (amb 1 2 3 4 5)) (mary (amb 1 2 3 4 5))) (begin (require (distinct? (list betty ethel joan kitty mary))) (require (xor (eq? kitty 2) (eq? betty 3))) (require (xor (eq? ethel 1) (eq? joan 2))) (require (xor (eq? joan 3) (eq? ethel 5))) (require (xor (eq? kitty 2) (eq? mary 4))) (require (xor (eq? mary 4) (eq? betty 1))) '((betty ,betty) (ethel ,ethel) (joan ,joan) (kitty ,kitty) (mary ,mary)))))) (liars)