(match
  (w leaf)
  (match
    (let:tree:cf leaf (let:tree:cf node (w var)))
    (match
      (let:tree:cf (w node) (let:tree:cf leaf (let:tree:cf (w{mono} node) (w{mono} var))))
      (w{l2xy mono}
        (let:tree:cf
          (tick app)
          (match:tuple
            (match
              (w leaf)
              (ite
                (tick (let:tree:cf node (let:tree:cf node (let:tree:cf (w{mono} node) (w{mono} var)))))
                (let:tree:cf node (let:tree:cf node (let:tree:cf node (w{mono} var))))
              )
            )
          )
        )
      )
    )
  )
)
