edits

diff --git a/topics/week12_list_and_tree_zippers.mdwn b/topics/week12_list_and_tree_zippers.mdwn
index 2f5d5dc..3f7ca7a 100644 (file)
--- a/topics/week12_list_and_tree_zippers.mdwn
+++ b/topics/week12_list_and_tree_zippers.mdwn
@@ -213,7 +213,7 @@ siblings of the focussed tree:
 
     Branch (Leaf 2, Leaf 3), ([], [Leaf 4])
 
 
     Branch (Leaf 2, Leaf 3), ([], [Leaf 4])
 

-We still need to add the rest of the context.  But just computed that
+We still need to add the rest of the context.  But we just computed that

 context a minute ago.  It was ([Leaf 1], []).  If we add it here, we get:
 
     Branch (Leaf 2, Leaf 3), ([], [Leaf 4], ([Leaf 1], [])
 context a minute ago.  It was ([Leaf 1], []).  If we add it here, we get:
 
     Branch (Leaf 2, Leaf 3), ([], [Leaf 4], ([Leaf 1], [])


@@ -223,13 +223,13 @@ Here's the type suggested by this idea:
     type context = Root | Context of (tree list) * (tree list) * context
     type zipper = tree * context
 
     type context = Root | Context of (tree list) * (tree list) * context
     type zipper = tree * context
 

-We can gloss `Context of (tree list) * (tree list) * context` as 
-`Context of (left siblings) * (right siblings) * (context of parent)`.
+We can gloss the triple `(tree list) * (tree list) * context` as 
+`(left siblings) * (right siblings) * (context of parent)`.

 
 Here, then, is the full tree zipper we've been looking for:
 
 
 Here, then, is the full tree zipper we've been looking for:
 

-  (Branch [Leaf 2; Leaf 3],
-   Context ([], [Leaf 4], Context ([Leaf 1], [], Root)))
+    (Branch [Leaf 2; Leaf 3],
+     Context ([], [Leaf 4], Context ([Leaf 1], [], Root)))

 
 Just as with the simple list zipper, note that elements that are near
 the focussed element in the tree are near the focussed element in the
 
 Just as with the simple list zipper, note that elements that are near
 the focussed element in the tree are near the focussed element in the