(define true (lambda (t) (lambda (f) t)))
(define false (lambda (t) (lambda (f) f)))
- 8. Define a "neg" operator that negates "true" and "false".
-
+* Define a "neg" operator that negates "true" and "false".
Expected behavior:
(((neg true) 10) 20)
evaluates to 10.
- 9. Define an "and" operator.
-
- 10. Define an "xor" operator.
+* Define an "and" operator.
+* Define an "xor" operator.
(If you haven't seen this term before, here's a truth table:
true xor true = false
)
- 11. Inspired by our definition of boolean values, propose a data structure
- capable of representing one of the two values "black" or "white".
-
+* 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:
a definition for each of "black" and "white". (Do it in both lambda calculus
and also in Racket.)
-12. Now propose a data structure capable of representing one of the three values
+* Now propose a data structure capable of representing one of the three values
"red" "green" or "blue," based on the same model. (Do it in both lambda
calculus and also in Racket.)