+(See [[hints/Assignment 4 hint 3]] if you need some hints.)
</OL>
</OL>
@@ -80,5+82,8 @@ If we gave you such a `Y1` and `Y2`, how would you implement the above definitio
<LI>(More challenging.) Using our derivation of Y from the [[Week2]] notes as a model, construct a pair `Y1` and `Y2` that behave in the way described.
<LI>(More challenging.) Using our derivation of Y from the [[Week2]] notes as a model, construct a pair `Y1` and `Y2` that behave in the way described.
+
+(See [[hints/Assignment 4 hint 4]] if you need some hints.)