apply-plural := λ(: function-name String)(: ft Type)(: pt Type)(: do-specialize U8)(: blame AST). (: (
   (let r (: LEOF List<Type>))
   (match ft (
      ()
      ( (TAnd( t1 t2 )) (
         (set r (+(
            (apply-plural( function-name t1 pt do-specialize blame ))
            (apply-plural( function-name t2 pt do-specialize blame ))
         )))
      ))
      ( (TGround( 'Arrow_s (LCons( frt (LCons( fpt LEOF )) )) )) (
         (if (can-unify( fpt pt )) (
            (set r (cons( ft r )))
         ) ())
      ))
      ( _ () )
   ))
   r
) List<Type>);