http://practical-scheme.net/wiliki/wiliki.cgi?Scheme%3acall%2fcc%e3%81%a8%e5%89%af%e4%bd%9c%e7%94%a8 [id:sumii:20061121] 前に紹介したFamkeの論文にも、 We implement threads by using first class continuations in Clean, without the usage of call/CC (with, according to Thielecke [6] can be dangerous). ... [6] Hayo Thielecke. Using a continuation twice and its implications for the expressive power of call/CC. High