deep-hash := λ(: tt Type). (: (
   (let return 0_u64)
   (match tt (
      ()
      ( TAny () )
      ( (TVar v) (set return (deep-hash v)) )
      ( (TAnd( lt rt )) (
         (set return (+(
            (deep-hash lt)
            (deep-hash rt)
         )))
      ))
      ( (TGround( tag ps )) (
         (set return (+(
            (deep-hash tag)
            (deep-hash ps)
         )))
      ))
   ))
   return
) U64);

deep-hash := λ(: tt List<Type>). (: (
   (let return 0_u64)
   (match tt (
      ()
      ( LEOF () )
      ( (LCons( t1 ts )) (
         (set return (+(
            (deep-hash ts)
            (deep-hash t1)
         )))
      ))
   ))
   return
) U64);