let succ = \n s z. s (n s z) in
let mult = \m n s. m (n s) in
let length = Y (\length l. isNil l 0 (succ (length (tail l)))) in
-let pred = \n. isZero n 0 (length (tail (n (\p. makeList meh p) nil))) in
+let pred = \n. isZero n 0 (length (tail (n (\p. makeList meh p) nil)))
+in
let leq = \m n. isZero(n pred m) in
let eq = \m n. and (leq m n)(leq n m) in
interpreter; web pages are not supposed to be that computationally
intensive).
-3. (Easy) Write a function `listLenEq` that returns true just in case two lists have the
+3. (Easy) Write a function `listLenEq` that returns true just in case
+two lists have the
same length. That is,
- listLenEq mylist (makeList meh (makeList meh (makeList meh nil))) ~~> true
+ listLenEq mylist (makeList meh (makeList meh (makeList meh nil)))
+ ~~> true
listLenEq mylist (makeList meh (makeList meh nil))) ~~> false
-4. (Still easy) Now write the same function, but don't use the length function.
+4. (Still easy) Now write the same function, but don't use the length
+function.
-5. In assignment 2, we discovered that version 3-type lists (the ones that
+5. In assignment 2, we discovered that version 3-type lists (the ones
+that
work like Church numerals) made it much easier to define operations
-like `map` and `filter`. But now that we have recursion in our toolbox,
+like `map` and `filter`. But now that we have recursion in our
+toolbox,
reasonable map and filter functions for version 1 lists are within our
-reach. Give definitions for `map` and a `filter` for verson 1 type lists.
+reach. Give definitions for `map` and a `filter` for verson 1 type
+lists.
#Computing with trees#