That’s not the same edit. In one case, you’re appending to the document. In the other, you’re appending to a child element. However, appending “a fallacy” to the document in both cases would produce different results due to text positioning.<p>I think if you want #1, you need an isomorphism between documents and their appearance. This article only asks for a homomorphism, where different documents are allowed to produce the same result.