edits

diff --combined assignment_3_evaluator.mdwn
index eb3c18b,c910064..28693f4
--- 1/assignment_3_evaluator.mdwn
--- 2/assignment_3_evaluator.mdwn
+++ b/assignment_3_evaluator.mdwn
@@@ -5,24 -5,23 +5,25 @@@ Here are the definitions pre-loaded fo
  let true = \x y. x in
  let false = \x y. y in
  let and = \l r. l (r true false) false in
- let make_pair = \f s g. g f s in
- let get_fst = true in
- let get_snd = false in
- let empty = make_pair true junk in
- let isempty = \x. x get_fst in
- let make_list = \h t. make_pair false (make_pair h t) in
- let head = \l. isempty l err (l get_snd get_fst) in
- let tail = \l. isempty l err (l get_snd get_snd) in
 +let or = \l r. l true r in
++;
+ let make\_pair = \f s g. g f s in
+ let get\_fst = true in
+ let get\_snd = false in
+ let empty = make\_pair true junk in
+ let isempty = \x. x get\_fst in
+ let make\_list = \h t. make\_pair false (make\_pair h t) in
+ let head = \l. isempty l err (l get\_snd get\_fst) in
+ let tail = \l. isempty l err (l get\_snd get\_snd) in
  ;
  ; a list of numbers to experiment on
- let mylist = make_list 1 (make_list 2 (make_list 3 empty)) in
+ let mylist = make\_list 1 (make\_list 2 (make\_list 3 empty)) in
  ;
  ; church numerals
  let iszero = \n. n (\x. false) true in
  let succ = \n s z. s (n s z) in
  let mul = \m n s. m (n s) in
- let pred = (\shift n. n shift (make_pair 0 0) get_snd) (\p. p (\x y. make_pair (succ x) x))  in
+ let pred = (\shift n. n shift (make\_pair 0 0) get\_snd) (\p. p (\x y. make\_pair (succ x) x))  in
  let leq = \m n. iszero(n pred m) in
  let eq = \m n. and (leq m n)(leq n m) in
  ;
@@@ -32,34 -31,18 +33,35 @@@ let Y = \f. (\h. f (h h)) (\h. f (h h)
  let length = Y (\length l. isempty l 0 (succ (length (tail l)))) in
  ;
  ; synonyms
- let makePair = make_pair in
- let fst = get_fst in
- let snd = get_snd in
+ let makePair = make\_pair in
+ let fst = get\_fst in
+ let snd = get\_snd in
  let nil = empty in
  let isNil = isempty in
- let makeList = make_list in
+ let makeList = make\_list in
  let isZero = iszero in
  let mult = mul in
  ;
 +let t1 = (make_list 1 empty) in
 +let t2 = (make_list 2 empty) in
 +let t3 = (make_list 3 empty) in
 +let t12 = (make_list t1 (make_list t2 empty)) in
 +let t23 = (make_list t2 (make_list t3 empty)) in
 +let ta = (make_list t1 t23) in
 +let tb = (make_list t12 t3) in
 +let tc = (make_list t1 (make_list t23 empty)) in
 +;
 +;sum-leaves t1 ~~> 1
 +;sum-leaves t2 ~~> 2
 +;sum-leaves t3 ~~> 3
 +;sum-leaves t12 ~~> 3
 +;sum-leaves t23 ~~> 5
 +;sum-leaves ta ~~> 6
 +;sum-leaves tb ~~> 6
 +;
  length (tail mylist)
  </textarea>
+ 
  <input id="PARSE" value="Normalize" type="button">
  <input id="ETA" type="checkbox">do eta-reductions too
  <noscript><p>You may not see it because you have JavaScript turned off. Uffff!</p></noscript>