The "documented information" you want is mentioned in the article. Guido links to a blog post by Jeremy Siek and a paper by Vitousek, Siek and Baker. Read the b

The "documented information" you want is mentioned in the article. Guido links to a blog post by Jeremy Siek and a paper by Vitousek, Siek and Baker. Read the blog post, section "Why subtyping does not work". http://wphomes.soic.indiana.edu/jsiek/what-is-gradual-typing/ http://wphomes.soic.indiana.edu/jsiek/what-is-gradual-typing... http://wphomes.soic.indiana.edu/jsiek/files/2014/03/retic-python.pdf http://wphomes.soic.indiana.edu/jsiek/files/2014/03/retic-py...