Vladimir Propp presents an excellent argument in his "Morphology of the Folktale." In testing his hypothesis he compares the themes of about 100 tales and comes out with a formula, ultimately coming to the conclusion that there is really only one fairy tale in its structure. He takes "a description of the tale according to its component parts and [compares] the relationship of these components to each other and to the whole" (Tatar 382). There is a significant amount of repeating functions in these classic stories. Propp defines the function "as an act of a character, defined from the point of view of its significance for the course of the action." (Tatar 383).

Functions are stable elements in the story, they never change. "The number of functions known to the fairy tale are limited," while the stories vary greatly (Tatar 384). He explains that there is a law for the sequence of...