fix another typo on ski_evaluator

[lambda.git] / exercises / assignment5.mdwn

diff --git a/exercises/assignment5.mdwn b/exercises/assignment5.mdwn
index 7bcbbee..5dd1cbb 100644 (file)
--- a/exercises/assignment5.mdwn
+++ b/exercises/assignment5.mdwn
@@ -252,6 +252,8 @@ Again, we've left some gaps. (The use of `type` for the first line in Haskell an
 
 15. Choose one of these languages and fill in the gaps to complete the definition.
 
 
 15. Choose one of these languages and fill in the gaps to complete the definition.
 

+<a id="occurs_free"></a>
+

 16. Write a function `occurs_free` that has the following type:
 
         occurs_free : identifier -> lambda_term -> bool
 16. Write a function `occurs_free` that has the following type:
 
         occurs_free : identifier -> lambda_term -> bool


@@ -329,7 +331,7 @@ any type `α`, as long as your function is of type `α -> α` and you have a bas
         -- Or this:
         let sysf_true = (\y n -> y) :: Sysf_bool a
 
         -- Or this:
         let sysf_true = (\y n -> y) :: Sysf_bool a
 

-    Note that in both OCaml and the Haskell code, the generalization `∀'a` on the free type variable `'a` is implicit. If you really want to, you can supply it explicitly in Haskell by saying:
+    Note that in both OCaml and Haskell code, the generalization `∀α` on the free type variable `α` is implicit. If you really want to, you can supply it explicitly in Haskell by saying:

 
         :set -XExplicitForAll
         let { sysf_true :: forall a. Sysf_bool a; ... }
 
         :set -XExplicitForAll
         let { sysf_true :: forall a. Sysf_bool a; ... }


@@ -408,7 +410,7 @@ Be sure to test your proposals with simple lists. (You'll have to `sysf_cons` up
         # k 1 true ;;
         - : int = 1
 
         # k 1 true ;;
         - : int = 1
 

-    If you can't understand how one term can have several types, recall our discussion in this week's notes of "principal types". (WHERE?)
+    If you can't understand how one term can have several types, recall our discussion in this week's notes of "principal types".