(define true (lambda (t) (lambda (f) t)))
(define false (lambda (t) (lambda (f) f)))
-(8). Define a "neg" operator that negates "true" and "false".
-Expected behavior: (((neg true) 10) 20) evaluates to 20,
-(((neg false) 10) 20) evaluates to 10.
+* 8. Define a "neg" operator that negates "true" and "false".
+Expected behavior:
-(9). Define an "and" operator.
+ (((neg true) 10) 20)
-10. Define an "xor" operator. (If you haven't seen this term before, here's a truth table:
+evaluates to 20, and
+
+ (((neg false) 10) 20)
+
+evaluates to 10.
+
+* 9. Define an "and" operator.
+
+* 10. Define an "xor" operator. (If you haven't seen this term before, here's a truth table:
true xor true = false
true xor false = true
false xor true = true
false xor false = false
+
)
-11. Inspired by our definition of boolean values, propose a data structure
+* 11. Inspired by our definition of boolean values, propose a data structure
capable of representing one of the two values "black" or "white". If we have
one of those values, call it a black-or-white-value, we should be able to
write: