2. What does `[ 10*x + y | y from [4], x from [1, 2, 3] ]` evalaute to?
-3. Using either Kapulet's or Haskell's list comprehension syntax, write an expression that transforms `[3, 1, 0, 2]` into `[3, 3, 3, 1, 2, 2]`.
+3. Using either Kapulet's or Haskell's list comprehension syntax, write an expression that transforms `[3, 1, 0, 2]` into `[3, 3, 3, 1, 2, 2]`. [[Here is a hint|assignment3 hints]], if you need it.
-<!-- Hint. Define a function `dup (n, x)` that creates a list of *n* copies of `x`. Then use list comprehensions to transform `[3, 1, 0, 2]` into `[[3, 3, 3], [1], [], [2, 2]]`. Then use `join` to "flatten" the result. -->
## Lists
6. Continuing to encode lists in terms of their left-folds, what should `last` be, where `last [a, b, c]` should result in `c`. Let `last []` result in whatever `err` is bound to.
-7. Continuing to encode lists in terms of their left-folds, how should we write `head`? This is challenging.
+7. Continuing to encode lists in terms of their left-folds, how should we write `head`? This is challenging. [[Here is a hint|assignment3 hints]], if you need it.
-<!-- Hint.
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--->
## Numbers