X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=exercises%2F_assignment4.mdwn;fp=exercises%2F_assignment4.mdwn;h=226741e14c1f136f738019543eeea238351aa9fa;hp=33c7e779c648643843d734ea71696bb54252c593;hb=f18d270f9c73466e1ec28afb184a0fdb3fc343af;hpb=5c234a526ad9ecc96ae9d17b6f74de53a0354444

diff --git a/exercises/_assignment4.mdwn b/exercises/_assignment4.mdwn
index 33c7e779..226741e1 100644
--- a/exercises/_assignment4.mdwn
+++ b/exercises/_assignment4.mdwn
@@ -107,10 +107,10 @@ satisfies the following constraints, for any finite natural number `n`:
         n ^ inf == inf
         leq n inf == true
 
-    (Note, though, that with some notions of infinite numbers, operations like `+` and `*` are defined in such a way that `inf + n` is different from `n + inf`, and does exceed `inf`.)
+    (Note, though, that with *some* notions of infinite numbers, like [[!wiki ordinal numers]], operations like `+` and `*` are defined in such a way that `inf + n` is different from `n + inf`, and does exceed `inf`.)
 
-9. Prove that `add 1 ξ <~~> ξ`, where `ξ` is the fixed
-point you found in (1).  What about `add 2 ξ <~~> ξ`?  
+9. Prove that `add ξ 1 <~~> ξ`, where `ξ` is the fixed
+point you found in (1).  What about `add ξ 2 <~~> ξ`?  
 
 Comment: a fixed point for the successor function is an object such that it
 is unchanged after adding 1 to it.  It makes a certain amount of sense