> They use the beginning student [1] and intermediate student [2] versions of the language. To elaborate, one of the further benefits of multiple student langu

> They use the beginning student [1] and intermediate student [2] versions of the language. To elaborate, one of the further benefits of multiple student languages like these is that concepts are taught incrementally. For instance, in the beginning student language, lists are explicitly shown as `(cons a (cons b '()))` before they are shown as `(list a b)` in intermediate student language.