content: -- Y COMBINATOR ---------------------------------------------------------------
  
  on |Y|(f)
      script
          on |λ|(y)
              script
                  on |λ|(x)
                      y's |λ|(y)'s |λ|(x)
                  end |λ|
              end script
  
              f's |λ|(result)
          end |λ|
      end script
  
      result's |λ|(result)
  end |Y|
  
  
  -- TEST -----------------------------------------------------------------------
  on run
  
      -- Factorial
      script fact
          on |λ|(f)
              script
                  on |λ|(n)
                      if n = 0 then return 1
                      n * (f's |λ|(n - 1))
                  end |λ|
              end script
          end |λ|
      end script
  
  
      -- Fibonacci
      script fib
          on |λ|(f)
              script
                  on |λ|(n)
                      if n = 0 then return 0
                      if n = 1 then return 1
                      (f's |λ|(n - 2)) + (f's |λ|(n - 1))
                  end |λ|
              end script
          end |λ|
      end script
  
      {facts:map(|Y|(fact), enumFromTo(0, 11)), fibs:map(|Y|(fib), enumFromTo(0, 20))}
  
      --> {facts:{1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, 39916800},
  
      --> fibs:{0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987,
      --           1597, 2584, 4181, 6765}}
  
  end run
  
  
  -- GENERIC FUNCTIONS FOR TEST -------------------------------------------------
  
  -- map :: (a -> b) -> [a] -> [b]
  on map(f, xs)
      tell mReturn(f)
          set lng to length of xs
          set lst to {}
          repeat with i from 1 to lng
              set end of lst to |λ|(item i of xs, i, xs)
          end repeat
          return lst
      end tell
  end map
  
  -- enumFromTo :: Int -> Int -> [Int]
  on enumFromTo(m, n)
      if n < m then
          set d to -1
      else
          set d to 1
      end if
      set lst to {}
      repeat with i from m to n by d
          set end of lst to i
      end repeat
      return lst
  end enumFromTo
  
  -- Lift 2nd class handler function into 1st class script wrapper
  -- mReturn :: Handler -> Script
  on mReturn(f)
      if class of f is script then
          f
      else
          script
              property |λ| : f
          end script
      end if
  end mReturn
  