 
   Use negative values to look up expression values relative to the current one.
   For instance, v(-1) returns the result of the last evaluated expression.
+
+  ## Examples
+
+      iex(1)> "hello" <> " world"
+      "hello world"
+      iex(2)> 40 + 2
+      42
+      iex(3)> foo = "bar"
+      "bar"
+      iex(4)> v(-2)
+      42
+      iex(5)> v(3)
+      "bar"
+      iex(6)> v()
+      "bar"
+
   """
   def v(n \\ -1) do
     IEx.History.nth(history(), n) |> elem(2)


  @doc """
  Prints information about the data type of any given term.
  
  ## Examples

      iex> i(1..5)
      
  Will print:
    
      Term
        1..5
      Data type

      t(Enum)
      t(Enum.t/0)
      t(Enum.t)

  """
  defmacro t(term)
  defmacro t({:/, _, [{{:., _, [mod, fun]}, _, []}, arity]}) do
