sizeof-type := λ(: tt Type). (: (
   (let sz 0_u64)
   (match tt (
      ()
      ( TAny () )
      ( (TVar _) () )
      ( (TGround( class LEOF )) (set sz (size-of-class class)) )
      ( (TGround( 'Sized_s (LCons( (TGround( szp LEOF )) LEOF )) )) (
         (set sz (to-u64 szp))
      ))
      ( (TGround( 'Array_s (LCons( TAny (LCons( p1 LEOF )) )) )) (
         (set sz 8_u64)
      ))
      ( (TGround( 'Cons_s (LCons( p2 (LCons( p1 LEOF )) )) )) (
         (set sz (+(
            (sizeof-aligned p1)
            (sizeof-aligned p2)
         )))
      ))
      ( (TGround( 'Field_s (LCons( (TGround( szp LEOF )) (LCons( p1 LEOF )) )) )) (
         (set sz (*( (sizeof-type p1) (to-u64 szp) )))
      ))
      ( (TGround( tag _ )) (
         (match (.lookup( type-complex-fields-index tag (Tuple( TAny TAny )) )) (
            ()
            ( (Tuple( TAny TAny )) () )
            ( (Tuple( bt at )) (
               (let ctx (unify( bt tt )))
               (let arg-types (substitute( ctx at )))
               (set sz (+( 8_u64 (sizeof-aligned arg-types) )))
            ))
         ))
      ))
      ( (TAnd( lt rt )) (
         (if (sizeof-type lt) (
            (set sz (sizeof-type lt))
         ) (
            (set sz (sizeof-type rt))
         ))
      ))
      ( _ (
         (print 'Unexpected\sType\ssizeof-type\s_s)
         (print tt)(print '\n_s)(exit 1_u64)
      ))
   ))
   sz
) U64);