== := λ(: lt Type)(: rt Type). (: (
   (let r 0_u64)
   (match (Tuple( lt rt )) (
      ()
      ( (Tuple( TAny TAny )) (set r 1_u64) )
      ( (Tuple( (TVar lv) (TVar rv) )) (set r (==( lv rv ))) )
      ( (Tuple( (TAnd( llt rlt )) (TAnd( lrt rrt )) )) (
         (if (==( llt lrt )) (
            (if (==( rlt rrt )) (
               (set r 1_u64)
            ) ())
         ) ())
      ))
      ( (Tuple( (TGround( ln lps )) (TGround( rn rps )) )) (
         (if (==( ln rn )) (
            (if (==( lps rps )) (
               (set r 1_u64)
            ) ())
         ) ())
      ))
      ( _ () )
   ))
   r
) U64);