--- /dev/null
+#lang racket
+
+(require "amb-eli.rkt")
+(require "distinct.rkt")
+
+(define (xor x y)
+ (cond [(and x y) #f]
+ [(and (not x) (not y)) #f]
+ [else #t]))
+
+(define (liars)
+ (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)])
+ (assert (distinct? (list betty ethel joan kitty mary)))
+ (assert (xor (= kitty 2) (= betty 3)))
+ (assert (xor (= ethel 1) (= joan 2)))
+ (assert (xor (= joan 3) (= ethel 5)))
+ (assert (xor (= kitty 2) (= mary 4)))
+ (assert (xor (= mary 4) (= betty 1)))
+ (list (list 'betty betty)
+ (list 'ethel ethel)
+ (list 'joan joan)
+ (list 'kitty kitty)
+ (list 'mary mary))))
+
+(collect (liars))
+
+;; '(((betty 3) (ethel 5) (joan 2) (kitty 1) (mary 4)))